Reimplement Expr::isConstantExpr in terms of Expr::Evaluate. This fixes PR2832.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/staticinit.c b/test/CodeGen/staticinit.c
index 50c837a..196d931 100644
--- a/test/CodeGen/staticinit.c
+++ b/test/CodeGen/staticinit.c
@@ -18,3 +18,9 @@
   static char a[10];
   static char *b = a;
 }
+
+struct s { void *p; };
+
+void foo(void) {
+  static struct s var = {((void*)&((char*)0)[0])};
+}