Emit an error when attempting to generate IR for SEH __try

Currently we silently omit the code in the try and finally bodies, which
is pretty bad.  This way we fail loudly.

llvm-svn: 190809
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 0c2cfc4..1748621 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -1697,3 +1697,7 @@
 
   return EHResumeBlock;
 }
+
+void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
+  CGM.ErrorUnsupported(&S, "SEH __try");
+}