Fix memdep's handling of invokes when finding the dependency of another call
instruction.  This fixes some Ada miscompiles reported in PR2324.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51069 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 4af7b42..7a6633f 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -129,7 +129,7 @@
       
       // FreeInsts erase the entire structure
       pointerSize = ~0UL;
-    } else if (isa<CallInst>(QI)) {
+    } else if (CallSite::get(QI).getInstruction() != 0) {
       AliasAnalysis::ModRefBehavior result =
                    AA.getModRefBehavior(CallSite::get(QI));
       if (result != AliasAnalysis::DoesNotAccessMemory) {