build:wafsamba: refactored the gcc-based dependency calculation

[github at samba.org]

New comment by obnoxxx on Samba Github repository

https://github.com/samba-team/samba/pull/31#issuecomment-157994164
Comment:
withdrawing my RB for now:
configuring succeeds but build fails with backtrace and a message
"The gccdeps module has been upgraded. Please run distclean and reconfigure"

Can it be that the patch "use the upstream version.." needs to be changed as follows:


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 buildtools/wafsamba/wscript | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/buildtools/wafsamba/wscript b/buildtools/wafsamba/wscript
index 34775a6..03d16b1 100755
--- a/buildtools/wafsamba/wscript
+++ b/buildtools/wafsamba/wscript
@@ -554,7 +554,8 @@ def build(bld):
     if 'gccdeps' in sys.modules and (os.path.exists(p) or not bld.env.GCCDEPS):
         if os.path.exists(p):
             os.remove(p)
-        raise Utils.WafError('The gccdeps module has been upgraded. Please run distclean and reconfigure')
+        if bld.env.GCCDEPS:
+            raise Utils.WafError('The gccdeps module has been upgraded. Please run distclean and reconfigure')
 
     # give a more useful message if the source directory has moved
     relpath = os_path_relpath(bld.curdir, bld.srcnode.abspath())
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~