[HotColdSplitting] Disable outlining landingpad instructions (PR39917)

It's currently not safe to outline landingpad instructions (see
llvm.org/PR39917). Like @llvm.eh.typeid.for, the order and content of
previous landingpad instructions in a function alters the lowering of
subsequent landingpads by renumbering type info ID's. Outlining a
landingpad therefore breaks exception handling & unwinding.

llvm-svn: 348870
diff --git a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
index 704ddbe..5d989a4 100644
--- a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
+++ b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
@@ -125,7 +125,7 @@
 
 /// Check whether it's safe to outline \p BB.
 static bool mayExtractBlock(const BasicBlock &BB) {
-  return !BB.hasAddressTaken();
+  return !BB.hasAddressTaken() && !BB.isEHPad();
 }
 
 /// Check whether \p Region is profitable to outline.