Revert the vector part of Enrico's change in r198729;

it is causing an llvm assert when run against
test/functionalities/data-formatter/rdar-10642615,

Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file llvm/include/llvm/Support/Casting.h, line 239.

llvm-svn: 198809

lldb/source/Symbol/ClangASTType.cpp

@@ -3245,7 +3245,7 @@ ClangASTType::GetChildClangTypeAtIndex (ExecutionContext *exe_ctx,
         case clang::Type::ExtVector:
             if (idx_is_valid)
             {
-                const VectorType *array = cast<VectorType>(GetQualType().getTypePtr());
+                const VectorType *array = cast<VectorType>(parent_qual_type.getTypePtr());
                 if (array)
                 {
                     ClangASTType element_type (m_ast, array->getElementType());