[Support] Make error banner optional in logAllUnhandledErrors

In a lot of places an empty string was passed as the ErrorBanner to
logAllUnhandledErrors. This patch makes that argument optional to
simplify the call sites.

llvm-svn: 346604
diff --git a/llvm/unittests/ExecutionEngine/Orc/RemoteObjectLayerTest.cpp b/llvm/unittests/ExecutionEngine/Orc/RemoteObjectLayerTest.cpp
index ae408a0..09224c2 100644
--- a/llvm/unittests/ExecutionEngine/Orc/RemoteObjectLayerTest.cpp
+++ b/llvm/unittests/ExecutionEngine/Orc/RemoteObjectLayerTest.cpp
@@ -112,10 +112,9 @@
 
   auto Channels = createPairedQueueChannels();
 
-  auto ReportError =
-    [](Error Err) {
-      logAllUnhandledErrors(std::move(Err), llvm::errs(), "");
-    };
+  auto ReportError = [](Error Err) {
+    logAllUnhandledErrors(std::move(Err), llvm::errs());
+  };
 
   // Copy the bytes out of the test object: the copy will be used to verify
   // that the original is correctly transmitted over RPC to the mock layer.
@@ -225,10 +224,9 @@
 
   auto Channels = createPairedQueueChannels();
 
-  auto ReportError =
-    [](Error Err) {
-      logAllUnhandledErrors(std::move(Err), llvm::errs(), "");
-    };
+  auto ReportError = [](Error Err) {
+    logAllUnhandledErrors(std::move(Err), llvm::errs());
+  };
 
   RPCEndpoint ClientEP(*Channels.first, true);
   RemoteObjectClientLayer<RPCEndpoint> Client(ClientEP, ReportError);
@@ -489,10 +487,9 @@
 
   auto Channels = createPairedQueueChannels();
 
-  auto ReportError =
-    [](Error Err) {
-      logAllUnhandledErrors(std::move(Err), llvm::errs(), "");
-    };
+  auto ReportError = [](Error Err) {
+    logAllUnhandledErrors(std::move(Err), llvm::errs());
+  };
 
   RPCEndpoint ClientEP(*Channels.first, true);
   RemoteObjectClientLayer<RPCEndpoint> Client(ClientEP, ReportError);