[MinGW][clang-shlib] Build only when LLVM_LINK_LLVM_DYLIB is enabled

Otherwise it's easy to hit 2^16 DLL exports limit.

Differential Revision: https://reviews.llvm.org/D89225

Author: mati865

clang/tools/CMakeLists.txt

@@ -15,7 +15,9 @@ add_clang_subdirectory(c-index-test)
 
 add_clang_subdirectory(clang-rename)
 add_clang_subdirectory(clang-refactor)
-if(UNIX OR MINGW)
+# For MinGW we only enable shared library if LLVM_LINK_LLVM_DYLIB=ON.
+# Without that option resulting library is too close to 2^16 DLL exports limit.
+if(UNIX OR (MINGW AND LLVM_LINK_LLVM_DYLIB))
   add_clang_subdirectory(clang-shlib)
 endif()