Revert "libclang: Add static build support for Windows" and

follow-up "libclang: Make shared object symbol exporting by default"

This reverts commit 7a7c753b0c.
This reverts commit 7ff1f55a12.

They broke building libclang.dll on Windows, see
https://reviews.llvm.org/D74564

clang/include/clang-c/Platform.h

@@ -18,23 +18,14 @@
 
 LLVM_CLANG_C_EXTERN_C_BEGIN
 
-/* Windows DLL import/export. */
-#ifndef CINDEX_NO_EXPORTS
-  #define CINDEX_EXPORTS
-#endif
-#ifdef _WIN32
-  #ifdef CINDEX_EXPORTS
-    #ifdef _CINDEX_LIB_
-      #define CINDEX_LINKAGE __declspec(dllexport)
-    #else
-      #define CINDEX_LINKAGE __declspec(dllimport)
-    #endif
+/* MSVC DLL import/export. */
+#ifdef _MSC_VER
+  #ifdef _CINDEX_LIB_
+    #define CINDEX_LINKAGE __declspec(dllexport)
+  #else
+    #define CINDEX_LINKAGE __declspec(dllimport)
   #endif
-#elif defined(CINDEX_EXPORTS) && defined(__GNUC__)
-  #define CINDEX_LINKAGE __attribute__((visibility("default")))
-#endif
-
-#ifndef CINDEX_LINKAGE
+#else
   #define CINDEX_LINKAGE
 #endif
 

clang/tools/libclang/CMakeLists.txt

@@ -77,11 +77,11 @@ if(MSVC)
   set(LLVM_EXPORTED_SYMBOL_FILE)
 endif()
 
-if(LLVM_ENABLE_PIC OR NOT LIBCLANG_BUILD_STATIC)
+if(LLVM_ENABLE_PIC OR WIN32)
   set(ENABLE_SHARED SHARED)
 endif()
 
-if(NOT LLVM_ENABLE_PIC OR LIBCLANG_BUILD_STATIC)
+if((NOT LLVM_ENABLE_PIC OR LIBCLANG_BUILD_STATIC) AND NOT WIN32)
   set(ENABLE_STATIC STATIC)
 endif()
 
@@ -113,14 +113,6 @@ add_clang_library(libclang ${ENABLE_SHARED} ${ENABLE_STATIC} INSTALL_WITH_TOOLCH
   Support
   )
 
-if(ENABLE_STATIC)
-  foreach(name libclang obj.libclang libclang_static)
-    if (TARGET ${name})
-      target_compile_definitions(${name} PUBLIC CINDEX_NO_EXPORTS)
-    endif()
-  endforeach()
-endif()
-
 if(ENABLE_SHARED)
   if(WIN32)
     set_target_properties(libclang