Add handling for GlobalAliases in ExecutionEngine::getConstantValue.

Patch by Brad Moody. Thanks Brad!

https://reviews.llvm.org/D42160

llvm-svn: 333217
diff --git a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
index dae0ea8..ae96c7f 100644
--- a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -903,6 +903,9 @@
     Result.IntVal = cast<ConstantInt>(C)->getValue();
     break;
   case Type::PointerTyID:
+    while (auto *A = dyn_cast<GlobalAlias>(C)) {
+      C = A->getAliasee();
+    }
     if (isa<ConstantPointerNull>(C))
       Result.PointerVal = nullptr;
     else if (const Function *F = dyn_cast<Function>(C))