add stub routines stackalloc() and stackfree().
run oldstack on g0's stack, just like newstack does,
so that oldstack can free the old stack.
R=r
DELTA=53 (44 added, 0 deleted, 9 changed)
OCL=20404
CL=20433
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index e37786e..a0cbac3 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -277,6 +277,8 @@
void minit(void);
Func* findfunc(uint64);
int32 funcline(Func*, uint64);
+void* stackalloc(uint32);
+void stackfree(void*);
/*
* mutual exclusion locks. in the uncontended case,
