lib/Basic/Targets.cpp: Fix __declspec() on Mingw-w64.

It should be defined as-is. Some headers would detect existence of __declspec and use one.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123690 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed