clang-format: use `pb` as a canonical raw string delimiter for google style

[krasimir]

Summary

This updates the canonical text proto raw string delimiter to pb for Google style, moving codebases towards a simpler and more consistent style.

Also updates a behavior where the canonical delimiter was not applied for raw strings with empty delimiters detected via well-known enclosing functions that expect a text proto, effectively making the canonical delimiter more viral. This feature is not widely used so this should be safe and more in line with promoting the canonicity of the canonical delimiter.

[krasimir]

clang-format: use pb as a canonical raw string delimiter for google style

[krasimir]

Update tests

[krasimir]

Collect commits

[sammccall]

Also fixes a bug where the canonical delimiter was not applied for raw strings with empty delimiters detected via well-known enclosing functions that expect a text proto.

Are you sure this was a bug rather than intended behavior? Seems... not unreasonable.

CanonicalDelemiter seems very rarely used so far though, so should be safe.

[krasimir]

In D97688#2610657, @sammccall wrote:

Also fixes a bug where the canonical delimiter was not applied for raw strings with empty delimiters detected via well-known enclosing functions that expect a text proto.

Are you sure this was a bug rather than intended behavior? Seems... not unreasonable.

CanonicalDelemiter seems very rarely used so far though, so should be safe.

Good point! I agree that is a reasonable behavior as well, so it's not a bug but a change of behavior. Agree that this should be safe.

clang/lib/Format/Format.cpp

GoogleStyle.RawStringFormats = {
               "cpp",
               "Cpp",
               "CPP",
               "c++",
               "C++",
           },
           /*EnclosingFunctionNames=*/
           {},
-          /*CanonicalDelimiter=*/"",
+          /*CanonicalDelimiter=*/"pb",
           /*BasedOnStyle=*/"google",
       },
       {
           FormatStyle::LK_TextProto,
           /*Delimiters=*/
           {
               "pb",
               "PB",