Remove some duplicates from emitted compilation traces

When multiple threads concurrently attempt to compile the same method,
`--trace-compile` could emit duplicate `precompile` statements. This
small tweak eliminates one source of these duplicates.

src/codegen-stubs.c

@@ -43,10 +43,11 @@ JL_DLLEXPORT void jl_generate_fptr_for_unspecialized_fallback(jl_code_instance_t
     jl_atomic_store_release(&unspec->invoke, &jl_fptr_interpret_call);
 }
 
-JL_DLLEXPORT void jl_compile_codeinst_fallback(jl_code_instance_t *unspec)
+JL_DLLEXPORT int jl_compile_codeinst_fallback(jl_code_instance_t *unspec)
 {
     // Do nothing. The caller will notice that we failed to provide a an ->invoke and trigger
     // appropriate fallbacks.
+    return 0;
 }
 
 JL_DLLEXPORT uint32_t jl_get_LLVM_VERSION_fallback(void)

src/gf.c

@@ -2568,12 +2568,12 @@ jl_code_instance_t *jl_compile_method_internal(jl_method_instance_t *mi, size_t
         }
 
         JL_GC_PUSH1(&codeinst);
-        jl_compile_codeinst(codeinst);
+        int did_compile = jl_compile_codeinst(codeinst);
 
         if (jl_atomic_load_relaxed(&codeinst->invoke) == NULL) {
             // Something went wrong. Bail to the fallback path.
             codeinst = NULL;
-        } else {
+        } else if (did_compile) {
             record_precompile_statement(mi);
         }
         JL_GC_POP();

src/jitlayers.cpp

@@ -461,19 +461,22 @@ void jl_extern_c_impl(jl_value_t *declrt, jl_tupletype_t *sigt)
 }
 
 extern "C" JL_DLLEXPORT_CODEGEN
-void jl_compile_codeinst_impl(jl_code_instance_t *ci)
+int jl_compile_codeinst_impl(jl_code_instance_t *ci)
 {
+    int newly_compiled = 0;
     if (jl_atomic_load_relaxed(&ci->invoke) != NULL) {
-        return;
+        return newly_compiled;
     }
     JL_LOCK(&jl_codegen_lock);
     if (jl_atomic_load_relaxed(&ci->invoke) == NULL) {
         ++SpecFPtrCount;
         uint64_t start = jl_typeinf_timing_begin();
         _jl_compile_codeinst(ci, NULL, *jl_ExecutionEngine->getContext());
         jl_typeinf_timing_end(start, 0);
+        newly_compiled = 1;
     }
     JL_UNLOCK(&jl_codegen_lock); // Might GC
+    return newly_compiled;
 }
 
 extern "C" JL_DLLEXPORT_CODEGEN

src/julia_internal.h

@@ -1727,7 +1727,7 @@ JL_DLLEXPORT uint32_t jl_crc32c(uint32_t crc, const char *buf, size_t len);
 #define IR_FLAG_INBOUNDS 0x01
 
 JL_DLLIMPORT void jl_generate_fptr_for_unspecialized(jl_code_instance_t *unspec);
-JL_DLLIMPORT void jl_compile_codeinst(jl_code_instance_t *unspec);
+JL_DLLIMPORT int jl_compile_codeinst(jl_code_instance_t *unspec);
 JL_DLLIMPORT int jl_compile_extern_c(LLVMOrcThreadSafeModuleRef llvmmod, void *params, void *sysimg, jl_value_t *declrt, jl_value_t *sigt);
 
 typedef struct {