[llvm] [llvm] revisions to `LLVM_ABI` export macro definitions (PR #144598)

[Andrew Rogers via llvm-commits]

================
@@ -206,25 +190,24 @@
 #define LLVM_TEMPLATE_ABI __declspec(dllimport)
 #define LLVM_EXPORT_TEMPLATE
 #endif
-#define LLVM_ABI_FRIEND LLVM_ABI
 #define LLVM_ABI_EXPORT __declspec(dllexport)
-#elif defined(__ELF__) || defined(__MINGW32__) || defined(_AIX) ||             \
+#elif __has_attribute(visibility)
+#if defined(__ELF__) || defined(__MINGW32__) || defined(_AIX) ||               \
     defined(__MVS__) || defined(__CYGWIN__)
-#define LLVM_ABI LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
-#define LLVM_ABI_FRIEND
-#define LLVM_TEMPLATE_ABI LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
+#define LLVM_ABI __attribute__((visibility("default")))
----------------
andrurogerz wrote:

`LLVM_ATTRIBUTE_VISIBILITY_DEFAULT` is defined like this earlier in the file, and I'd prefer to be consistent:
```
#define LLVM_ATTRIBUTE_VISIBILITY_DEFAULT __attribute__((visibility("default")))
```

https://github.com/llvm/llvm-project/pull/144598