CXX-3296 fix build if GCC/GNU/Clang/MSVC macro defined (mongodb#1409)

* guard Clang/GCC/GNU/MSVC macros

Author: kevinAlbs

src/bsoncxx/include/bsoncxx/v1/detail/postlude.hpp

@@ -64,6 +64,10 @@
 #pragma pop_macro("BSONCXX_PRIVATE_WARNINGS_DISABLE")
 #pragma pop_macro("BSONCXX_PRIVATE_WARNINGS_POP")
 #pragma pop_macro("BSONCXX_PRIVATE_WARNINGS_PUSH")
+#pragma pop_macro("Clang")
+#pragma pop_macro("GCC")
+#pragma pop_macro("GNU")
+#pragma pop_macro("MSVC")
 #endif
 
 #if !defined(BSONCXX_PRIVATE_V1_INSIDE_MACRO_GUARD_SCOPE)

src/bsoncxx/include/bsoncxx/v1/detail/prelude.hpp

@@ -102,6 +102,14 @@
 #undef BSONCXX_PRIVATE_WARNINGS_PUSH
 #pragma push_macro("BSONCXX_PRIVATE_UNREACHABLE")
 #undef BSONCXX_PRIVATE_UNREACHABLE
+#pragma push_macro("Clang") // Guard since BSONCXX_PRIVATE_WARNINGS_DISABLE(Clang(...)) assumes Clang is not defined.
+#undef Clang
+#pragma push_macro("GCC") // Guard since BSONCXX_PRIVATE_WARNINGS_DISABLE(GCC(...)) assumes GCC is not defined.
+#undef GCC
+#pragma push_macro("GNU") // Guard since BSONCXX_PRIVATE_WARNINGS_DISABLE(GNU(...)) assumes GNU is not defined.
+#undef GNU
+#pragma push_macro("MSVC") // Guard since BSONCXX_PRIVATE_WARNINGS_DISABLE(MSVC(...)) assumes MSVC is not defined.
+#undef MSVC
 #endif
 
 ///

src/bsoncxx/test/CMakeLists.txt

@@ -123,6 +123,10 @@ if(ENABLE_MACRO_GUARD_TESTS)
             BSONCXX_PRIVATE_WARNINGS_DISABLE_IMPL_FOR_MSVC
             BSONCXX_PRIVATE_WARNINGS_POP
             BSONCXX_PRIVATE_WARNINGS_PUSH
+            Clang
+            GCC
+            GNU
+            MSVC
 
             # bsoncxx/v1/detail/prelude.hpp
             BSONCXX_PRIVATE_V1_INSIDE_MACRO_GUARD_SCOPE