Add an AST node for __leave statements, hook it up.

Codegen is still missing (and I won't work on that), but __leave is now
as implemented as __try and friends.

llvm-svn: 212425
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index ffcab07..1bbda5c 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -1632,3 +1632,7 @@
 void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
   CGM.ErrorUnsupported(&S, "SEH __try");
 }
+
+void CodeGenFunction::EmitSEHLeaveStmt(const SEHLeaveStmt &S) {
+  CGM.ErrorUnsupported(&S, "SEH __leave");
+}