[not part of build] NFRAMES == 2 for alignment reasons.

gc/boehm/gc_priv.h

@@ -225,7 +225,7 @@ typedef char * ptr_t;	/* A generic pointer to which we can add	*/
  * Number of frames and arguments to save in objects allocated by
  * debugging allocator.
  */
-#   define NFRAMES 1    /* Number of frames to save. Even for		*/
+#   define NFRAMES 2    /* Number of frames to save. Even for		*/
                         /* alignment reasons.				*/
 #   define NARGS 0      /* Mumber of arguments to save for each call.	*/
 

gc/boehm/misc.c

@@ -809,7 +809,7 @@ static char* pc2name(word pc, char name[], long size)
 extern void MWUnmangle(const char *mangled_name, char *unmangled_name, size_t buffersize);
 extern int GC_address_to_source(char* codeAddr, char symbolName[256], char fileName[256], UInt32* fileOffset);
 
-#if NFRAMES > 1
+#if NFRAMES > 2
 
 void GC_print_callers(struct callinfo info[NFRAMES])
 {