AOM_CHECK_MEM_ERROR: add an assert for a valid jmp target

callers of AOM_CHECK_MEM_ERROR() expect failures to not return

Bug: aomedia:3276
Change-Id: I0adf0320c801a580f0f2de12557e0534d6d91606

aom_mem/aom_mem.h

diff --git a/aom_mem/aom_mem.h b/aom_mem/aom_mem.h
index 15cc43d..b332139 100644
--- a/aom_mem/aom_mem.h
+++ b/aom_mem/aom_mem.h
@@ -12,6 +12,8 @@
 #ifndef AOM_AOM_MEM_AOM_MEM_H_
 #define AOM_AOM_MEM_AOM_MEM_H_
 
+#include <assert.h>
+
 #include "aom/aom_integer.h"
 #include "config/aom_config.h"
 
@@ -57,6 +59,7 @@
 #if CONFIG_DEBUG
 #define AOM_CHECK_MEM_ERROR(error_info, lval, expr)                         \
   do {                                                                      \
+    assert((error_info)->setjmp);                                           \
     lval = (expr);                                                          \
     if (!lval)                                                              \
       aom_internal_error(error_info, AOM_CODEC_MEM_ERROR,                   \
@@ -66,6 +69,7 @@
 #else
 #define AOM_CHECK_MEM_ERROR(error_info, lval, expr)       \
   do {                                                    \
+    assert((error_info)->setjmp);                         \
     lval = (expr);                                        \
     if (!lval)                                            \
       aom_internal_error(error_info, AOM_CODEC_MEM_ERROR, \