fate.sh: add support for build-only FATE instances

If the "build_only" variable is set in the configuration file, the
FATE client will skip running tests and just compile all targets.
Signed-off-by: Martin Storsjö <martin@martin.st>

doc/fate.texi

@@ -120,6 +120,7 @@ samples=/path/to/fate/samples
 workdir=                                # directory in which to do all the work
 fate_recv="ssh -T fate@@fate.libav.org"  # command to submit report
 comment=                                # optional description
+build_only=     # set to "yes" for a compile-only instance that skips tests
 
 # the following are optional and map to configure options
 arch=

tests/fate.sh

@@ -66,6 +66,7 @@ compile()(
 )
 
 fate()(
+    test "$build_only" = "yes" && return
     cd ${build} || return
     ${make} ${makeopts} -k fate
 )