Remove an assertion in UnreachableCodeChecker that can be triggered by bugs in other checkers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/UnreachableCodeChecker.cpp b/lib/Checker/UnreachableCodeChecker.cpp
index fd98a7a..7a56c7f 100644
--- a/lib/Checker/UnreachableCodeChecker.cpp
+++ b/lib/Checker/UnreachableCodeChecker.cpp
@@ -188,8 +188,11 @@
 // There will never be more than one predecessor.
 bool UnreachableCodeChecker::isInvalidPath(const CFGBlock *CB,
                                            const ParentMap &PM) {
-  // Assert this CFGBlock only has one or zero predecessors
-  assert(CB->pred_size() == 0 || CB->pred_size() == 1);
+  // We only expect a predecessor size of 0 or 1. If it is >1, then an external
+  // condition has broken our assumption (for example, a sink being placed by
+  // another check). In these cases, we choose not to report.
+  if (CB->pred_size() > 1)
+    return true;
 
   // If there are no predecessors, then this block is trivially unreachable
   if (CB->pred_size() == 0)