Subzero: Improve the behavior of resizing vectors.

src/IceGlobalContext.cpp

Index: src/IceGlobalContext.cpp
diff --git a/src/IceGlobalContext.cpp b/src/IceGlobalContext.cpp
index 15cc40d2c5ad278e954c084b5cd773117ddc021a..c96db74df1f8a3cc38823045579648971e2ebd07 100644
--- a/src/IceGlobalContext.cpp
+++ b/src/IceGlobalContext.cpp
@@ -375,7 +375,7 @@ namespace {
 // Ensure Pending is large enough that Pending[Index] is valid.
 void resizePending(std::vector<EmitterWorkItem *> &Pending, uint32_t Index) {
   if (Index >= Pending.size())
-    Pending.resize(Index + 1);
+    Utils::reserveAndResize(Pending, Index + 1);
 }
 
 } // end of anonymous namespace