build: fix windows build

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/5656051

src/all.bat

@@ -9,11 +9,14 @@ echo all.bat must be run from go\src
 goto end
 :ok
 
+set GOOLDPATH=%PATH%
+
 call make.bat --no-banner
 if %GOBUILDFAIL%==1 goto end
 call run.bat --no-rebuild
 if %GOBUILDFAIL%==1 goto end
-..\bin\tool\dist banner
+go tool dist banner
 
 :end
+set PATH=%GOOLDPATH%
 if x%GOBUILDEXIT%==x1 exit %GOBUILDFAIL%

src/run.bat

@@ -3,14 +3,8 @@
 :: license that can be found in the LICENSE file.
 @echo off
 
-set GOOLDPATH=%PATH%
 set GOBUILDFAIL=0
 
-..\bin\tool\dist env -wp >env.bat
-if errorlevel 1 goto fail
-call env.bat
-del env.bat
-
 rem TODO avoid rebuild if possible
 
 if x%1==x--no-rebuild goto norebuild
@@ -44,4 +38,3 @@ goto end
 set GOBUILDFAIL=1
 
 :end
-set PATH=%GOOLDPATH%