Skip the error message in case of colorless BB.

Author: sylvain-audi

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -675,6 +675,8 @@ class RuntimeCallInserter {
       // funclet opbundles are only valid in monochromatic BBs.
       // Note that unreachable BBs are seen as colorless by colorEHFunclets()
       // and will be DCE'ed later.
+      if (Colors.empty())
+        continue;
       if (Colors.size() != 1) {
         OwnerFn->getContext().emitError(
             "Instruction's BasicBlock is not monochromatic");