Warnings from parser are dropped on the floor

[benesch]

What version of protobuf and what language are you using?
Version: master
Language: n/a

What operating system (Linux, Windows, ...) and version?

macOS 12.0 (but not applicable)

What runtime / compiler are you using (e.g., python version or gcc version)

n/a

What did you do?

Invoked protoc --descriptor_set_out=/dev/null bad.proto on this input:

// bad.proto
message bad_to_the_bone {}

What did you expect to see

This warning about snake case names:

protobuf/src/google/protobuf/compiler/parser.cc

Lines 765 to 767 in 01e84b1

	"Message name should be in UpperCamelCase. Found: " +
	message->name() +
	". See https://developers.google.com/protocol-buffers/docs/style");

What did you see instead?

Nothing.

Make sure you include information that can help us debug (full error message, exception listing, stack trace, logs).