Initial commit of the 'landingpad' instruction.

This implements the 'landingpad' instruction. It's used to indicate that a basic
block is a landing pad. There are several restrictions on its use (see
LangRef.html for more detail). These restrictions allow the exception handling
code to gather the information it needs in a much more sane way.

This patch has the definition, implementation, C interface, parsing, and bitcode
support in it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137501 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/BasicBlock.cpp

@@ -348,3 +348,15 @@ void BasicBlock::replaceSuccessorsPhiUsesWith(BasicBlock *New) {
     }
   }
 }
+
+/// isLandingPad - Return true if this basic block is a landing pad. I.e., it's
+/// the destination of the 'unwind' edge of an invoke instruction.
+bool BasicBlock::isLandingPad() const {
+  return isa<LandingPadInst>(getFirstNonPHI());
+}
+
+/// getLandingPadInst() - Return the landingpad instruction associated with
+/// the landing pad.
+LandingPadInst *BasicBlock::getLandingPadInst() {
+  return dyn_cast<LandingPadInst>(getFirstNonPHI());
+}