Rename ObjcInterfaceDecl::getIsForwardDecl() to isForwardDecl().
Rename ObjcProtocolDecl::getIsForwardProtoDecl() to isForwardDecl().
Rename ObjcInterfaceDecl::setIsForwardDecl() to setForwardDecl().
Rename ObjcProtocolDecl::setIsForwardProtoDecl() to setForwardDecl().

Two reasons:

#1: boolean predicates should start with "is".
#2: Since these two sets of methods represent the same concept, they should be named the same (polymorphism is good:-)

llvm-svn: 42545