runtime: sizeclass in MSpan should be int32.

R=golang-dev, minux.ma, dave, rsc
CC=golang-dev
https://golang.org/cl/6643046

diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h
index ac3cfa8d6a6f35b2247627fc03c07d112a23840d..e221faae37fbe4b05ef5dd5e46e41ff0601b2c95 100644 (file)
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -358,7 +358,7 @@ struct MSpan
        uintptr npages;         // number of pages in span
        MLink   *freelist;      // list of free objects
        uint32  ref;            // number of allocated objects in this span
-       uint32  sizeclass;      // size class
+       int32   sizeclass;      // size class
        uintptr elemsize;       // computed from sizeclass or from npages
        uint32  state;          // MSpanInUse etc
        int64   unusedsince;    // First time spotted by GC in MSpanFree state