CDRIVER-5813 remove misplaced define BSON_IF_MSVC (#1790)

* define `BSON_IF_MSVC` and `BSON_IF_GNU_LIKE` as empty for unsupported compilers

Author: kevinAlbs

src/common/src/common-atomic-private.h

@@ -57,7 +57,6 @@ enum mcommon_memory_order {
 #ifdef MCOMMON_USE_LEGACY_GCC_ATOMICS
 #undef BSON_IF_GNU_LIKE
 #define BSON_IF_GNU_LIKE(...)
-#define BSON_IF_MSVC(...)
 #define MCOMMON_IF_GNU_LEGACY_ATOMICS(...) __VA_ARGS__
 #else
 #define MCOMMON_IF_GNU_LEGACY_ATOMICS(...)

src/libbson/src/bson/bson-atomic.h

@@ -78,7 +78,6 @@ enum BSON_GNUC_DEPRECATED bson_memory_order {
 #ifdef BSON_USE_LEGACY_GCC_ATOMICS
 #undef BSON_IF_GNU_LIKE
 #define BSON_IF_GNU_LIKE(...)
-#define BSON_IF_MSVC(...)
 #define BSON_IF_GNU_LEGACY_ATOMICS(...) __VA_ARGS__
 #else
 #define BSON_IF_GNU_LEGACY_ATOMICS(...)

src/libbson/src/bson/bson-compat.h

@@ -189,6 +189,10 @@ typedef signed char bool;
 #define BSON_IF_MSVC(...)
 /** Expands the arguments if compiling with GCC or Clang, otherwise empty */
 #define BSON_IF_GNU_LIKE(...) __VA_ARGS__
+#else
+/** Unsupported compiler. **/
+#define BSON_IF_MSVC(...)
+#define BSON_IF_GNU_LIKE(...)
 #endif
 
 #ifdef BSON_OS_WIN32