Add a test case that Objective-C bitfield access doesn't reach past end of
structure.

llvm-svn: 112911
diff --git a/SingleSource/UnitTests/ObjC/bitfield-access.m b/SingleSource/UnitTests/ObjC/bitfield-access.m
new file mode 100644
index 0000000..948918b
--- /dev/null
+++ b/SingleSource/UnitTests/ObjC/bitfield-access.m
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+@interface I0 { 
+@public
+    unsigned a:15;
+    unsigned b: 9;
+} 
+@end
+
+@implementation I0
+@end
+
+void f0(I0 *s) {
+    s->b = 1;
+}
+
+int main() {
+    char *p = valloc(4096*2);
+    mprotect(p+4096, 4096, 0);
+    I0 *s = (I0 *)(p+4096-4);
+
+    f0(s);
+
+    return 0;
+}
diff --git a/SingleSource/UnitTests/ObjC/bitfield-access.reference_output b/SingleSource/UnitTests/ObjC/bitfield-access.reference_output
new file mode 100644
index 0000000..ca916d0
--- /dev/null
+++ b/SingleSource/UnitTests/ObjC/bitfield-access.reference_output
@@ -0,0 +1 @@
+exit 0