Add a testcase for the vla and stack realignment warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108365 91177308-0d34-0410-b5e6-96231b3b80d8

test/FrontendC/vla-1.c

@@ -0,0 +1,7 @@
+// RUN: %llvmgcc -std=gnu99 %s -S |& grep {error: "is greater than the stack alignment" } 
+
+int foo(int a)
+{
+  int var[a] __attribute__((__aligned__(32)));
+  return 4;
+}