Add test intended for commit in r231317

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@233866 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rnk

test/Sema/pragma-section-invalid.c

@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s -triple x86_64-apple-darwin
+
+// expected-error@+1 {{argument to 'section' attribute is not valid for this target: mach-o section specifier requires a segment and section separated by a comma}}
+#pragma data_seg(".my_const")
+int a = 1;
+#pragma data_seg("__THINGY,thingy")
+int b = 1;