Sort and remove blank lines from .gitignore

.gitignore

@@ -1,8 +1,8 @@
-*.lock
 *.bak
 *.bc
 *.d
 *.i
+*.lock
 *.o
 *.orig
 *.pdb
@@ -13,25 +13,22 @@
 *.tmp
 *~
 .DS_Store
+.ccls*
 .ccmalloc
 .svn
 .vscode
 .yardoc
-.ccls*
-compile_flags.txt
-compile_commands.json
-cscope.files
-cscope.out
-tags
-
 /.git
-/bin
-/build
-/mruby-source-*.gem
-
 /benchmark/**/*.dat
 /benchmark/*.pdf
 /benchmark/*.png
-
+/bin
+/build
 /doc/api
 /doc/capi
+/mruby-source-*.gem
+compile_commands.json
+compile_flags.txt
+cscope.files
+cscope.out
+tags