config_autoconf, extutils_libbuilder: fix tests on x86_gcc2

haikuporter runs in a gcc2 environment when not building secondaryArch packages
on x86_gcc2, so some additional environment changes are needed so that gcc-x86
actually works.

dev-perl/extutils_libbuilder/extutils_libbuilder-0.08.recipe

@@ -32,6 +32,7 @@ BUILD_PREREQUIRES="
 
 if [ "$targetArchitecture" = x86_gcc2 ]; then
 	TEST_REQUIRES="
+		haiku_x86_devel
 		cmd:gcc_x86
 		"
 else
@@ -57,5 +58,9 @@ INSTALL()
 }
 
 TEST() {
+	if [ "$targetArchitecture" = x86_gcc2 ]; then
+		export CC=gcc-x86
+		export LD=gcc-x86
+	fi
 	./Build test
 }