Rust YJIT: Prune more C code (ruby#206)

* Remove yjit_core.c

* Remove yjit_codegen.c, yjit_codegen.h

* Avoid linking with rb_vm_insn_addr2opcode in test mode

Author: maximecb

common.mk

@@ -17794,9 +17794,6 @@ yjit.$(OBJEXT): {$(VPATH)}yjit.rb
 yjit.$(OBJEXT): {$(VPATH)}yjit.rbinc
 yjit.$(OBJEXT): {$(VPATH)}yjit_asm.c
 yjit.$(OBJEXT): {$(VPATH)}yjit_asm.h
-yjit.$(OBJEXT): {$(VPATH)}yjit_codegen.c
-yjit.$(OBJEXT): {$(VPATH)}yjit_codegen.h
-yjit.$(OBJEXT): {$(VPATH)}yjit_core.c
 yjit.$(OBJEXT): {$(VPATH)}yjit_core.h
 yjit.$(OBJEXT): {$(VPATH)}yjit_iface.c
 yjit.$(OBJEXT): {$(VPATH)}yjit_iface.h

yjit.c

@@ -496,8 +496,6 @@ rb_get_call_data_ci(struct rb_call_data* cd) {
     return cd->ci;
 }
 
-#include "yjit_core.c"
 #include "yjit_iface.c"
-#include "yjit_codegen.c"
 
 #endif // if JIT_ENABLED && PLATFORM_SUPPORTED_P

yjit/src/stats.rs

@@ -267,6 +267,7 @@ pub extern "C" fn rb_yjit_collect_binding_set() {
 #[no_mangle]
 pub extern "C" fn rb_yjit_count_side_exit_op(exit_pc: *const VALUE) -> *const VALUE
 {
+    #[cfg(not(test))]
     unsafe {
         // Get the opcode from the encoded insn handler at this PC
         let opcode = rb_vm_insn_addr2opcode((*exit_pc).as_ptr());