ignore MSVC project upgrade files

Signed-off-by: Satoshi Tanda <tanda.sat@gmail.com>
diff --git a/.gitignore b/.gitignore
index 0f12b41..5470fd8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -80,6 +80,7 @@
 packages/freebsd/ports/devel/capstone/distinfo
 
 # VisualStudio
+ProjectUpgradeLog.log
 Debug/
 Release/
 ipch/
@@ -87,6 +88,7 @@
 *.opensdf
 *.suo
 *.user
+*.backup
 *.VC.db
 *.VC.opendb