testing/php7-pecl-grpc: build failures on armv7, armhf

It fails to build with several errors:

error: cast to pointer from integer of difference size

/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h: In function '_upb_msg_map_set_value':
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h:458:25: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  458 |     upb_strview *strp = (upb_strview*)ent->val.val;
      |                         ^
In file included from /home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/cds.upb.c:10:
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h: In function '_upb_msg_map_set_value':
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/auth/common.upb.c: At top level:
cc1: error: unrecognized command line option '-Wno-parentheses-equality' [-Werror]
cc1: all warnings being treated as errors
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h:458:25: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  458 |     upb_strview *strp = (upb_strview*)ent->val.val;
      |                         ^
make: *** [Makefile:422: src/core/ext/upb-generated/envoy/api/v2/auth/common.lo] Error 1
In file included from /home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/auth/tls.upb.c:10:
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h: In function '_upb_msg_map_set_value':
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h:458:25: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  458 |     upb_strview *strp = (upb_strview*)ent->val.val;
      |                         ^
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/annotations/resource.upb.c: At top level:
cc1: error: unrecognized command line option '-Wno-parentheses-equality' [-Werror]
cc1: all warnings being treated as errors
make: *** [Makefile:418: src/core/ext/upb-generated/envoy/annotations/resource.lo] Error 1
In file included from /home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/cluster.upb.c:10:
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h: In function '_upb_msg_map_set_value':
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h:458:25: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  458 |     upb_strview *strp = (upb_strview*)ent->val.val;
      |                         ^
In file included from /home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/auth/secret.upb.c:10:
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h: In function '_upb_msg_map_set_value':
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/third_party/upb/upb/msg.h:458:25: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  458 |     upb_strview *strp = (upb_strview*)ent->val.val;
      |                         ^
/home/buildozer/aports/testing/php7-pecl-grpc/src/grpc-1.31.0/src/core/ext/upb-generated/envoy/api/v2/cds.upb.c: At top level:
cc1: error: unrecognized command line option '-Wno-parentheses-equality' [-Werror]

The package has been disabled on armv7 for now.

See: https://build.alpinelinux.org/buildlogs/build-edge-armv7/testing/php7-pecl-grpc/php7-pecl-grpc-1.31.0-r0.log