[msan] Remove unreachable blocks before instrumenting a function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170883 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Utils/Local.h

@@ -257,6 +257,11 @@ DbgDeclareInst *FindAllocaDbgDeclare(Value *V);
 bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
                                 DIBuilder &Builder);
 
+/// \brief Remove all blocks that can not be reached from the function's entry.
+///
+/// Returns true if any basic block was removed.
+bool removeUnreachableBlocks(Function &F);
+
 } // End llvm namespace
 
 #endif