Make linker output error stacks instead of their top level

include/asm/fstack.h

@@ -43,6 +43,7 @@ void fstk_RunInclude(char *tzFileName);
 void fstk_RunMacroArg(int32_t s);
 void fstk_Init(char *s);
 void fstk_Dump(void);
+void fstk_DumpToStr(char *buf, size_t len);
 void fstk_DumpStringExpansions(void);
 void fstk_AddIncludePath(char *s);
 uint32_t fstk_RunMacro(char *s);