Fixing php proto generation script to work properly during sync (#10395)

php/generate_descriptor_protos.sh

@@ -5,10 +5,10 @@
 
 set -e
 
-PROTOC=protoc
+PROTOC=$(realpath protoc)
 if [ ! -f $PROTOC ]; then
   bazel build -c opt //:protoc
-  PROTOC=bazel-bin/protoc
+  PROTOC=$(realpath bazel-bin/protoc)
 fi
 
 if test ! -e src/google/protobuf/stubs/common.h; then
@@ -19,16 +19,17 @@ __EOF__
   exit 1
 fi
 
-$PROTOC --php_out=internal:php/src google/protobuf/descriptor.proto
-$PROTOC --php_out=internal_generate_c_wkt:php/src \
-  src/google/protobuf/any.proto \
-  src/google/protobuf/api.proto \
-  src/google/protobuf/duration.proto \
-  src/google/protobuf/empty.proto \
-  src/google/protobuf/field_mask.proto \
-  src/google/protobuf/source_context.proto \
-  src/google/protobuf/struct.proto \
-  src/google/protobuf/type.proto \
-  src/google/protobuf/timestamp.proto \
-  src/google/protobuf/wrappers.proto
+pushd src
+$PROTOC --php_out=internal:../php/src google/protobuf/descriptor.proto
+$PROTOC --php_out=internal_generate_c_wkt:../php/src \
+  google/protobuf/any.proto \
+  google/protobuf/api.proto \
+  google/protobuf/duration.proto \
+  google/protobuf/empty.proto \
+  google/protobuf/field_mask.proto \
+  google/protobuf/source_context.proto \
+  google/protobuf/struct.proto \
+  google/protobuf/type.proto \
+  google/protobuf/timestamp.proto \
+  google/protobuf/wrappers.proto
 popd