build; allow MAKEFLAGS to be set outside the build scripts

R=rsc, r
CC=golang-dev
https://golang.org/cl/1231041

diff --git a/src/make.bash b/src/make.bash
index d8638145eab10c78b3576d216c57f234a6806e5e..b718bb9562fc1d6edf98e5fb7cf4e7cc264c5dad 100755 (executable)
--- a/src/make.bash
+++ b/src/make.bash
@@ -6,7 +6,8 @@
 set -e
 . ./env.bash
 
-export MAKEFLAGS=-j4
+MAKEFLAGS=${MAKEFLAGS:-"-j4"}
+export MAKEFLAGS
 unset CDPATH   # in case user has it set
 
 rm -f "$GOBIN"/quietgcc