Substitute "::std::" as "St".

llvm-svn: 82874
diff --git a/clang/test/CodeGenCXX/mangle-subst-std.cpp b/clang/test/CodeGenCXX/mangle-subst-std.cpp
new file mode 100644
index 0000000..a5ba3ab
--- /dev/null
+++ b/clang/test/CodeGenCXX/mangle-subst-std.cpp
@@ -0,0 +1,9 @@
+// RUN: clang-cc -emit-llvm %s -o - -triple=x86_64-apple-darwin9 | FileCheck %s
+
+namespace std {
+  struct A { A(); };
+  
+  // CHECK: define void @_ZNSt1AC1Ev
+  // CHECK: define void @_ZNSt1AC2Ev
+  A::A() { }
+};