modify /merge to /head in pull-request-build.
Merge pull request #6770 from ricardoquesada/label_fixes

Does not crash on Mac if the .ttf file is not found
Merge pull request #6750 from shujunqiao/pull-build-merge

modify /merge to /head in pull-request-build.[ci skip]
Adds a virtual method for loading native libraries.
Merge pull request #6771 from dumganhar/load-native-lib

[android] Adds a virtual method for loading native libraries.