Improve clarity/consistency of a few UsingDecl methods and related helpers.
No functionality change.

In Sema helper functions:
 * renamed isTypeName as HasTypenameKeyword
In UsingDecl:
 * renamed get/setUsingLocation to get/setUsingLoc
 * renamed is/setTypeName as has/setTypename



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186816 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 34fdbad..ca0b9ad 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -9385,7 +9385,7 @@
   TypeDecl *Ty;
   if (isa<UsingDecl>(D)) {
     UsingDecl *Using = cast<UsingDecl>(D);
-    assert(Using->isTypeName() &&
+    assert(Using->hasTypename() &&
            "UnresolvedUsingTypenameDecl transformed to non-typename using");
 
     // A valid resolved using typename decl points to exactly one type decl.