Bug#856452: gcc-7: allow disabling brig via nolang DEB_BUILD_OPTIONS

[Helmut Grohne <helmut@subdivi.de>]

Source: gcc-7
Version: 7-20170221-1
Severity: wishlist
User: helmutg@debian.org
Usertags: rebootstrap

Hi Matthias,

thank you for disabling brig in stage1 and stage2. It still is rightly
enabled in the unstaged cross compiler build. Since it is not needed for
bootstrapping, I'd like to disable brig entirely. That saves build time
and human time for figuring out why it doesn't work. The gcc-N source
package typically allows doing so by passing a suitable
DEB_BUILD_OPTIONS=nolang=... variable. The attached patch allows
disabling brig by passing brig in there. Please consider applying it.

Helmut

--- a/debian/rules.defs
+++ a/debian/rules.defs
@@ -843,6 +843,7 @@
   with_brigdev := yes
   with_libhsailrt := yes
 endif
+with_brig := $(call envfilt, brig, , , $(with_brig))

 ifeq ($(with_brig),yes)
   enabled_languages += brig