[ORC] Create a new SymbolStringPool by default in ExecutionSession constructor.

This makes the common case of constructing an ExecutionSession tidier.

llvm-svn: 329013
diff --git a/llvm/unittests/ExecutionEngine/Orc/RTDyldObjectLinkingLayerTest.cpp b/llvm/unittests/ExecutionEngine/Orc/RTDyldObjectLinkingLayerTest.cpp
index f52ee6b..650fd52 100644
--- a/llvm/unittests/ExecutionEngine/Orc/RTDyldObjectLinkingLayerTest.cpp
+++ b/llvm/unittests/ExecutionEngine/Orc/RTDyldObjectLinkingLayerTest.cpp
@@ -67,8 +67,7 @@
   bool DebugSectionSeen = false;
   auto MM = std::make_shared<MemoryManagerWrapper>(DebugSectionSeen);
 
-  SymbolStringPool SSP;
-  ExecutionSession ES(SSP);
+  ExecutionSession ES(std::make_shared<SymbolStringPool>());
 
   RTDyldObjectLinkingLayer ObjLayer(ES, [&MM](VModuleKey) {
     return RTDyldObjectLinkingLayer::Resources{
@@ -124,8 +123,7 @@
   if (!SupportsJIT)
     return;
 
-  SymbolStringPool SSP;
-  ExecutionSession ES(SSP);
+  ExecutionSession ES(std::make_shared<SymbolStringPool>());
 
   auto MM = std::make_shared<SectionMemoryManagerWrapper>();
 
@@ -209,8 +207,7 @@
   if (!SupportsJIT)
     return;
 
-  SymbolStringPool SSP;
-  ExecutionSession ES(SSP);
+  ExecutionSession ES(std::make_shared<SymbolStringPool>());
 
   auto MM = std::make_shared<SectionMemoryManagerWrapper>();
 
@@ -271,8 +268,7 @@
 }
 
 TEST_F(RTDyldObjectLinkingLayerExecutionTest, TestNotifyLoadedSignature) {
-  SymbolStringPool SSP;
-  ExecutionSession ES(SSP);
+  ExecutionSession ES(std::make_shared<SymbolStringPool>());
   RTDyldObjectLinkingLayer ObjLayer(
       ES,
       [](VModuleKey) {