sys-apps/grep: wire up USE=test-full

Signed-off-by: Sam James <sam@gentoo.org>

sys-apps/grep/grep-3.12.ebuild

@@ -25,7 +25,7 @@ fi
 
 LICENSE="GPL-3+"
 SLOT="0"
-IUSE="+egrep-fgrep nls pcre static"
+IUSE="+egrep-fgrep nls pcre static test-full"
 
 # We lack dev-libs/libsigsegv[static-libs] for now
 REQUIRED_USE="static? ( !sparc )"
@@ -74,6 +74,8 @@ src_prepare() {
 src_configure() {
 	use static && append-ldflags -static
 
+	export RUN_{VERY_,}EXPENSIVE_TESTS=$(usex test-full yes no)
+
 	# We used to turn this off unconditionally (bug #673524) but we now
 	# allow it for cases where libsigsegv is better for userspace handling
 	# of stack overflows.

sys-apps/grep/metadata.xml

@@ -16,6 +16,7 @@
 			No deprecation warnings are emitted when this
 			flag is enabled.
 		</flag>
+		<flag name="test-full">Run expensive tests (mostly CPU intensive).</flag>
 	</use>
 	<upstream>
 		<remote-id type="cpe">cpe:/a:gnu:grep</remote-id>