Add the 'resume' instruction for the new EH rewrite.

This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136589 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -1810,6 +1810,10 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
 void SelectionDAGBuilder::visitUnwind(const UnwindInst &I) {
 }
 
+void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {
+  llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!");
+}
+
 /// handleSmallSwitchCaseRange - Emit a series of specific tests (suitable for
 /// small case ranges).
 bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,