Rollup merge of rust-lang#122157 - dpaoliello:targetdesc, r=Nilstrieb

Add the new description field to Target::to_json, and add descriptions for some MSVC targets

The original PR to add a `description` field to `Target` (<rust-lang#121905>) didn't add the field to `Target::to_json`, which meant that the `check_consistency` testwould fail if you tried to set a description as it wouldn't survive round-tripping via JSON: https://github.com/rust-lang/rust/actions/runs/8180997936/job/22370052535#step:27:4967

This change adds the field to `Target::to_json`, and sets some descriptions to verify that it works correctly.

Author: matthiaskrgr

compiler/rustc_target/src/spec/mod.rs

@@ -3253,6 +3253,7 @@ impl ToJson for Target {
         }
 
         target_val!(llvm_target);
+        target_val!(description);
         d.insert("target-pointer-width".to_string(), self.pointer_width.to_string().to_json());
         target_val!(arch);
         target_val!(data_layout);

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_msvc.rs

@@ -7,7 +7,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "aarch64-pc-windows-msvc".into(),
-        description: None,
+        description: Some("ARM64 Windows MSVC".into()),
         pointer_width: 64,
         data_layout: "e-m:w-p:64:64-i32:32-i64:64-i128:128-n32:64-S128".into(),
         arch: "aarch64".into(),

compiler/rustc_target/src/spec/targets/i686_pc_windows_msvc.rs

@@ -23,7 +23,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "i686-pc-windows-msvc".into(),
-        description: None,
+        description: Some("32-bit MSVC (Windows 7+)".into()),
         pointer_width: 32,
         data_layout: "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
             i64:64-i128:128-f80:128-n8:16:32-a:0:32-S32"

compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs

@@ -23,7 +23,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "i686-pc-windows-msvc".into(),
-        description: None,
+        description: Some("32-bit Windows 7 support".into()),
         pointer_width: 32,
         data_layout: "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
             i64:64-i128:128-f80:128-n8:16:32-a:0:32-S32"

compiler/rustc_target/src/spec/targets/thumbv7a_pc_windows_msvc.rs

@@ -13,7 +13,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "thumbv7a-pc-windows-msvc".into(),
-        description: None,
+        description: Some("ARM32 Windows MSVC".into()),
         pointer_width: 32,
         data_layout: "e-m:w-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
         arch: "arm".into(),

compiler/rustc_target/src/spec/targets/x86_64_pc_windows_msvc.rs

@@ -10,7 +10,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "x86_64-pc-windows-msvc".into(),
-        description: None,
+        description: Some("64-bit MSVC (Windows 7+)".into()),
         pointer_width: 64,
         data_layout:
             "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128".into(),

compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs

@@ -9,7 +9,7 @@ pub fn target() -> Target {
 
     Target {
         llvm_target: "x86_64-win7-windows-msvc".into(),
-        description: None,
+        description: Some("64-bit Windows 7 support".into()),
         pointer_width: 64,
         data_layout:
             "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128".into(),