Add more debugging info around ResolveField.

To better diagnose the DCHECK that we have hit here:
https://android-build.googleplex.com/builds/git_master-art-host-linux-art-jit/6325844/logs/build.log

Test: test.py
Change-Id: If160b74055c27cd02bde27e29c7e7f731c458f4d
diff --git a/compiler/optimizing/instruction_builder.cc b/compiler/optimizing/instruction_builder.cc
index 1e7b48e..fe4a86e 100644
--- a/compiler/optimizing/instruction_builder.cc
+++ b/compiler/optimizing/instruction_builder.cc
@@ -1651,7 +1651,11 @@
                                                         dex_compilation_unit_->GetDexCache(),
                                                         class_loader,
                                                         is_static);
-  DCHECK_EQ(resolved_field == nullptr, soa.Self()->IsExceptionPending());
+  DCHECK_EQ(resolved_field == nullptr, soa.Self()->IsExceptionPending())
+      << "field="
+      << ((resolved_field == nullptr) ? "null" : resolved_field->PrettyField())
+      << ", exception="
+      << (soa.Self()->IsExceptionPending() ? soa.Self()->GetException()->Dump() : "null");
   if (UNLIKELY(resolved_field == nullptr)) {
     // Clean up any exception left by field resolution.
     soa.Self()->ClearException();