[gobject-introspection] Replace GNU -B extension with a more portable -I equivalent

[Jasper Lievisse Adriaanse <jasperla src gnome org>]

commit dbbb8b36f2573134d46d5a514a86cc82a18e89d9
Author: Jasper Lievisse Adriaanse <jasper humppa nl>
Date:   Tue Apr 26 17:58:29 2016 +0200

    Replace GNU -B extension with a more portable -I equivalent
    
    https://bugzilla.gnome.org/show_bug.cgi?id=765618

 tests/gi-tester |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/tests/gi-tester b/tests/gi-tester
index 51199dd..26e2259 100755
--- a/tests/gi-tester
+++ b/tests/gi-tester
@@ -19,19 +19,19 @@ case $targetname in
     exit 0
     ;;
 *-C)
-    diff -r -u -w -B -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
+    diff -r -u -w -I '^\s*$' -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
     exit $?
     ;;
 *-Python)
-    diff -r -u -w -B -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
+    diff -r -u -w -I '^\s*$' -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
     exit $?
     ;;
 *-Gjs)
-    diff -r -u -w -B -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
+    diff -r -u -w -I '^\s*$' -U 10 ${srcdir}/${targetbase}-expected ${builddir}/${targetbase}
     exit $?
     ;;
 *-sections.txt)
-    diff -u -w -B -U 10 ${srcdir}/${targetname::-4}-expected.txt ${builddir}/${targetname}
+    diff -u -w -I '^\s*$' -U 10 ${srcdir}/${targetname::-4}-expected.txt ${builddir}/${targetname}
     exit $?
     ;;
 *.py)