Migrate 2009-12-23-MissingSext.cpp from test/FrontendC++ and modify

for sext -> and difference.

llvm-svn: 138088

clang/test/CodeGenCXX/2009-12-23-MissingSext.cpp

@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+// The store of p.y into the temporary was not
+// getting extended to 32 bits, so uninitialized
+// bits of the temporary were used.  7366161.
+struct foo {
+  char x:8;
+  signed int y:24;
+};
+int bar(struct foo p, int x) {
+// CHECK: bar
+// CHECK: and {{.*}} 16777215
+// CHECK: and {{.*}} 16777215
+  x = (p.y > x ? x : p.y);
+  return x;
+// CHECK: ret
+}