fix mingw compile error.
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'