Remove /Za flag from Visual Studio compilation

According to Stephan T. Lavavej it is broken. See
http://comments.gmane.org/gmane.comp.compilers.clang.devel/21638

Reviewers: grosser
llvm-svn: 242773

polly/cmake/polly_macros.cmake

@@ -36,14 +36,6 @@ macro(add_polly_library name)
   if( LLVM_LINK_COMPONENTS )
     llvm_config(${name} ${LLVM_LINK_COMPONENTS})
   endif( LLVM_LINK_COMPONENTS )
-  if(MSVC)
-    get_target_property(cflag ${name} COMPILE_FLAGS)
-    if(NOT cflag)
-      set(cflag "")
-    endif(NOT cflag)
-    set(cflag "${cflag} /Za")
-    set_target_properties(${name} PROPERTIES COMPILE_FLAGS ${cflag})
-  endif(MSVC)
   install(TARGETS ${name}
     EXPORT LLVMExports
     LIBRARY DESTINATION lib