Exception and suspend count polling on JNI bridge return.

Change-Id: I0e5597fcbdcdb88100b18d63323e7ba8d27f13fe
diff --git a/src/assembler.cc b/src/assembler.cc
index 52d424a..8bd7625 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -54,6 +54,7 @@
   cursor_ = contents_;
   limit_ = ComputeLimit(contents_, kInitialBufferCapacity);
   fixup_ = NULL;
+  slow_path_ = NULL;
 #if defined(DEBUG)
   has_ensured_capacity_ = false;
   fixups_processed_ = false;