[cmake] Reenable libclang.dll when LLVM_ENABLE_PIC (llvm#138343)

This was disabled for Windows/Mingw in llvm#138343, but it's actually
linkable and is being used by some people.

Author: aeubanks

clang/tools/libclang/CMakeLists.txt

@@ -106,8 +106,7 @@ if (LLVM_EXPORTED_SYMBOL_FILE)
                      DEPENDS ${LIBCLANG_VERSION_SCRIPT_FILE})
 endif()
 
-if((NOT (WIN32 OR CYGWIN) AND LLVM_ENABLE_PIC) OR
-  ((WIN32 OR CYGWIN) AND NOT LIBCLANG_BUILD_STATIC))
+if(LLVM_ENABLE_PIC OR ((WIN32 OR CYGWIN) AND NOT LIBCLANG_BUILD_STATIC))
   set(ENABLE_SHARED SHARED)
 endif()