Fix LANG=C for readelf invocation in T14999

The test fails when used with LANG=fr_FR.UTF-8

testsuite/tests/codeGen/should_compile/Makefile

@@ -34,7 +34,7 @@ debug:
 T14999:
 	'$(TEST_HC)' $(TEST_HC_OPTS) -O2 -g -c T14999.cmm -o T14999.o
 	gdb --batch -ex 'file T14999.o' -ex 'disassemble stg_catch_frame_info' --nx | tr -s '[[:blank:]\n]'
-	readelf --debug-dump=frames-interp T14999.o | tr -s '[[:blank:]\n]'
+	LANG=C readelf --debug-dump=frames-interp T14999.o | tr -s '[[:blank:]\n]'
 
 T15196:
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O -ddump-asm T15196.hs | grep "jp " ; echo $$?