rename test

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64545 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/SemaObjC/objc-gc-attr.m b/test/SemaObjC/attr-objc-gc.m
similarity index 100%
rename from test/SemaObjC/objc-gc-attr.m
rename to test/SemaObjC/attr-objc-gc.m