Revert "Move kVRegSize to globals.h to reduce include dependencies."

This reverts commit 5ae7cdfe5b8da645d1fec61c76176e6a37e78fb9.

Reason for revert: Unknown crash in linker

Change-Id: Ib5646376e2e589a7a6c4d66e72caa1f208a15905
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 833b39e..f0c4ee0 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -35,6 +35,7 @@
 #include "optimizing_compiler_stats.h"
 #include "read_barrier_option.h"
 #include "stack.h"
+#include "stack_map.h"
 #include "utils/label.h"
 
 namespace art {