[Frontend] The macro that describes the Objective-C bool type should

be defined for non Objective-C code as well

rdar://29794915

Differential Revision: https://reviews.llvm.org/D28349


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@292617 91177308-0d34-0410-b5e6-96231b3b80d8