[coreboot-gerrit] Patch merged into coreboot/master: ecd202d Makefile: Check $CC variable returned from xcompile is not empty.

the following patch was just integrated into master:
commit ecd202d4dbc3ef88b42c063a2d70e92e5f3dd22a
Author: Andrew Wu 
Date:   Thu Sep 5 00:21:11 2013 +0800

Makefile: Check $CC variable returned from xcompile is not empty.

If xcompile can't find out suitable GCC compiler for i386/armv7, it
    will not set $CC_i386/$CC_armv7 variable. Makefile sets $CC variable
    from xcompile, and will print strange error messages when executing
    $CC program if $CC is empty.

Add checking to avoid this problem. If $CC is empty, also delete
    invalid .xcompile file, so Make can recreate this file next time.

Change-Id: Ia8d481d76ca52f3351cb99f05779d06947161c5d
    Signed-off-by: Andrew Wu

See http://review.coreboot.org/3905 for details.

-gerrit