[AST] Use ArrayRef in more interfaces

ArrayRef is a little better than passing around a pointer/length
pair.

No functional change is intended.

llvm-svn: 274732
diff --git a/clang/lib/AST/ASTDiagnostic.cpp b/clang/lib/AST/ASTDiagnostic.cpp
index f4961250..22de8bc 100644
--- a/clang/lib/AST/ASTDiagnostic.cpp
+++ b/clang/lib/AST/ASTDiagnostic.cpp
@@ -119,7 +119,7 @@
         if (DesugarArgument) {
           ShouldAKA = true;
           QT = Context.getTemplateSpecializationType(
-              TST->getTemplateName(), Args.data(), Args.size(), QT);
+              TST->getTemplateName(), Args, QT);
         }
         break;
       }
@@ -1060,8 +1060,7 @@
 
     Ty = Context.getTemplateSpecializationType(
              TemplateName(CTSD->getSpecializedTemplate()),
-             CTSD->getTemplateArgs().data(),
-             CTSD->getTemplateArgs().size(),
+             CTSD->getTemplateArgs().asArray(),
              Ty.getLocalUnqualifiedType().getCanonicalType());
 
     return Ty->getAs<TemplateSpecializationType>();