Rollup merge of #40153 - steveklabnik:alphabetize-unstable-book, r=frewsxcv

sort unstable book alphabetically

I made these the same order as they were in the compiler, but for no good reason. Much easier to find out what you need when they're sorted alphabetically

r? @frewsxcv

Author: steveklabnik

src/doc/unstable-book/src/SUMMARY.md

@@ -1,94 +1,94 @@
 [The Unstable Book](the-unstable-book.md)
 
-- [asm](asm.md)
-- [alloc_system](alloc-system.md)
+- [abi_msp430_interrupt](abi-msp430-interrupt.md)
+- [abi_ptx](abi-ptx.md)
+- [abi_sysv64](abi-sysv64.md)
+- [abi_unadjusted](abi-unadjusted.md)
+- [abi_vectorcall](abi-vectorcall.md)
+- [advanced_slice_patterns](advanced-slice-patterns.md)
 - [alloc_jemalloc](alloc-jemalloc.md)
-- [test](test.md)
+- [alloc_system](alloc-system.md)
+- [allocator](allocator.md)
+- [allow_internal_unstable](allow-internal-unstable.md)
+- [asm](asm.md)
+- [associated_consts](associated-consts.md)
+- [associated_type_defaults](associated-type-defaults.md)
+- [attr_literals](attr-literals.md)
+- [box_patterns](box-patterns.md)
+- [box_syntax](box-syntax.md)
+- [cfg_target_feature](cfg-target-feature.md)
+- [cfg_target_has_atomic](cfg-target-has-atomic.md)
+- [cfg_target_thread_local](cfg-target-thread-local.md)
+- [cfg_target_vendor](cfg-target-vendor.md)
+- [compiler_builtins](compiler-builtins.md)
 - [concat_idents](concat-idents.md)
-- [link_args](link-args.md)
-- [log_syntax](log-syntax.md)
-- [non_ascii_idents](non-ascii-idents.md)
-- [plugin_registrar](plugin-registrar.md)
-- [thread_local](thread-local.md)
-- [trace_macros](trace-macros.md)
+- [conservative_impl_trait](conservative-impl-trait.md)
+- [const_fn](const-fn.md)
+- [const_indexing](const-indexing.md)
+- [custom_attribute](custom-attribute.md)
+- [custom_derive](custom-derive.md)
+- [default_type_parameter_fallback](default-type-parameter-fallback.md)
+- [drop_types_in_const](drop-types-in-const.md)
+- [dropck_eyepatch](dropck-eyepatch.md)
+- [dropck_parametricity](dropck-parametricity.md)
+- [exclusive_range_pattern](exclusive-range-pattern.md)
+- [field_init_shorthand](field-init-shorthand.md)
+- [fundamental](fundamental.md)
+- [generic_param_attrs](generic-param-attrs.md)
+- [i128_type](i128-type.md)
+- [inclusive_range_syntax](inclusive-range-syntax.md)
 - [intrinsics](intrinsics.md)
 - [lang_items](lang-items.md)
+- [link_args](link-args.md)
+- [link_cfg](link-cfg.md)
 - [link_llvm_intrinsics](link-llvm-intrinsics.md)
 - [linkage](linkage.md)
-- [quote](quote.md)
-- [simd](simd.md)
-- [rustc_diagnostic_macros](rustc-diagnostic-macros.md)
-- [advanced_slice_patterns](advanced-slice-patterns.md)
-- [box_syntax](box-syntax.md)
-- [placement_in_syntax](placement-in-syntax.md)
-- [unboxed_closures](unboxed-closures.md)
-- [allocator](allocator.md)
-- [fundamental](fundamental.md)
+- [log_syntax](log-syntax.md)
+- [loop_break_value](loop-break-value.md)
+- [macro_reexport](macro-reexport.md)
 - [main](main.md)
+- [naked_functions](naked-functions.md)
 - [needs_allocator](needs-allocator.md)
-- [on_unimplemented](on-unimplemented.md)
-- [plugin](plugin.md)
-- [simd_ffi](simd-ffi.md)
-- [start](start.md)
-- [structural_match](structural-match.md)
-- [panic_runtime](panic-runtime.md)
 - [needs_panic_runtime](needs-panic-runtime.md)
-- [optin_builtin_traits](optin-builtin-traits.md)
-- [macro_reexport](macro-reexport.md)
-- [staged_api](staged-api.md)
+- [never_type](never-type.md)
 - [no_core](no-core.md)
-- [box_patterns](box-patterns.md)
-- [dropck_parametricity](dropck-parametricity.md)
-- [dropck_eyepatch](dropck-eyepatch.md)
-- [custom_attribute](custom-attribute.md)
-- [custom_derive](custom-derive.md)
+- [no_debug](no-debug.md)
+- [non_ascii_idents](non-ascii-idents.md)
+- [omit_gdb_pretty_printer_section](omit-gdb-pretty-printer-section.md)
+- [on_unimplemented](on-unimplemented.md)
+- [optin_builtin_traits](optin-builtin-traits.md)
+- [panic_runtime](panic-runtime.md)
+- [placement_in_syntax](placement-in-syntax.md)
+- [platform_intrinsics](platform-intrinsics.md)
+- [plugin](plugin.md)
+- [plugin_registrar](plugin-registrar.md)
+- [prelude_import](prelude-import.md)
+- [proc_macro](proc-macro.md)
+- [pub_restricted](pub-restricted.md)
+- [quote](quote.md)
+- [relaxed_adts](relaxed-adts.md)
+- [repr_simd](repr-simd.md)
 - [rustc_attrs](rustc-attrs.md)
-- [allow_internal_unstable](allow-internal-unstable.md)
+- [rustc_diagnostic_macros](rustc-diagnostic-macros.md)
+- [sanitizer_runtime](sanitizer-runtime.md)
+- [simd](simd.md)
+- [simd_ffi](simd-ffi.md)
 - [slice_patterns](slice-patterns.md)
-- [associated_consts](associated-consts.md)
-- [const_fn](const-fn.md)
-- [const_indexing](const-indexing.md)
-- [prelude_import](prelude-import.md)
+- [specialization](specialization.md)
+- [staged_api](staged-api.md)
+- [start](start.md)
+- [static_nobundle](static-nobundle.md)
 - [static_recursion](static-recursion.md)
-- [default_type_parameter_fallback](default-type-parameter-fallback.md)
-- [associated_type_defaults](associated-type-defaults.md)
-- [repr_simd](repr-simd.md)
-- [cfg_target_feature](cfg-target-feature.md)
-- [platform_intrinsics](platform-intrinsics.md)
-- [unwind_attributes](unwind-attributes.md)
-- [naked_functions](naked-functions.md)
-- [no_debug](no-debug.md)
-- [omit_gdb_pretty_printer_section](omit-gdb-pretty-printer-section.md)
-- [cfg_target_vendor](cfg-target-vendor.md)
 - [stmt_expr_attributes](stmt-expr-attributes.md)
+- [struct_field_attributes](struct-field-attributes.md)
+- [structural_match](structural-match.md)
+- [target_feature](target-feature.md)
+- [test](test.md)
+- [thread_local](thread-local.md)
+- [trace_macros](trace-macros.md)
 - [type_ascription](type-ascription.md)
-- [cfg_target_thread_local](cfg-target-thread-local.md)
-- [abi_vectorcall](abi-vectorcall.md)
-- [inclusive_range_syntax](inclusive-range-syntax.md)
-- [exclusive_range_pattern](exclusive-range-pattern.md)
-- [specialization](specialization.md)
-- [pub_restricted](pub-restricted.md)
-- [drop_types_in_const](drop-types-in-const.md)
-- [cfg_target_has_atomic](cfg-target-has-atomic.md)
-- [conservative_impl_trait](conservative-impl-trait.md)
-- [relaxed_adts](relaxed-adts.md)
-- [never_type](never-type.md)
-- [attr_literals](attr-literals.md)
-- [abi_sysv64](abi-sysv64.md)
+- [unboxed_closures](unboxed-closures.md)
 - [untagged_unions](untagged-unions.md)
-- [compiler_builtins](compiler-builtins.md)
-- [generic_param_attrs](generic-param-attrs.md)
-- [field_init_shorthand](field-init-shorthand.md)
-- [windows_subsystem](windows-subsystem.md)
-- [link_cfg](link-cfg.md)
+- [unwind_attributes](unwind-attributes.md)
 - [use_extern_macros](use-extern-macros.md)
-- [loop_break_value](loop-break-value.md)
-- [target_feature](target-feature.md)
-- [abi_ptx](abi-ptx.md)
-- [i128_type](i128-type.md)
-- [abi_unadjusted](abi-unadjusted.md)
-- [proc_macro](proc-macro.md)
-- [struct_field_attributes](struct-field-attributes.md)
-- [static_nobundle](static-nobundle.md)
-- [abi_msp430_interrupt](abi-msp430-interrupt.md)
-- [sanitizer_runtime](sanitizer-runtime.md)
+- [windows_subsystem](windows-subsystem.md)