Merge pull request grpc#13100 from muxi/supress-strict-prototype-warning

Supress strict prototype warning in v1.7.x

Merge pull request grpc#13055 from apolcyn/bump_v16x

Bump v16x branch to 1.6.7

Merge pull request grpc#12844 from apolcyn/backport_ruby_gc_rooted_bugs

Backport ruby non-GC-rooted variable fixes to 1.6.x

Merge pull request grpc#12806 from muxi/backport-12340

Backport grpc#12340: Allow unreachable code on iPhone

Merge pull request grpc#12758 from apolcyn/bump_v16x

Bump v1.6.x branch to 1.6.4

This is a patch release for gRPC Python

Fixes grpc#11887, grpc#9688

Merge pull request grpc#12632 from apolcyn/backport_google_rpc_status…

…_in_ruby

Backport grpc#12452 to 1.6.x

Merge pull request grpc#12504 from jtattermusch/bump_1_6_1

Bump version to 1.6.1

Merge pull request grpc#12320 from dgquintas/release_1.6.0

Release 1.6.0 version number change

Merge pull request grpc#12292 from stanley-cheung/php-backport-1_6-fe…

…atures

PHP: backport master features into v1.6.x branch