runtime: fix windows/amd64 build after pc-relative 6l change

TBR=iant
CC=golang-codereviews
https://golang.org/cl/131900043

diff --git a/src/pkg/runtime/sys_windows_amd64.s b/src/pkg/runtime/sys_windows_amd64.s
index 6dc13e293d8771f72012e2d00de16dc5398643ac..73b1ba6d8c1b609cb0e5014990eceb4a24d76c07 100644 (file)
--- a/src/pkg/runtime/sys_windows_amd64.s
+++ b/src/pkg/runtime/sys_windows_amd64.s
@@ -228,7 +228,8 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$0
        ADDQ    $8, SP
 
        // determine index into runtime·cbctxts table
-       SUBQ    $runtime·callbackasm(SB), AX
+       MOVQ    $runtime·callbackasm(SB), DX
+       SUBQ    DX, AX
        MOVQ    $0, DX
        MOVQ    $5, CX  // divide by 5 because each call instruction in runtime·callbacks is 5 bytes long
        DIVL    CX,