Remove support for legacy stringref text syntax

[tlively]

Removing support for the legacy syntax will allow us to avoid implementing
support for it in the new text parser.

[tlively]

Current dependencies on/for this PR:

• main
  • PR Remove support for legacy stringref text syntax #6289 👈
    • PR Update lit tests to parse with the new parser #6290

This stack of pull requests is managed by Graphite.

[kripken]

How are you defining "legacy stringref text syntax"?

[tlively]

Just the stuff marked with // Legacy syntax comments in the old parser. All the deleted forms take separate behavior modifiers as immediates and have new replacements that use single mnemonics that are more consistent with the rest of the language and already supported by the new parser.

[kripken]

Got it, thanks.

[tlively]

Merge activity

• Feb 8, 5:59 PM EST: @tlively started a stack merge that includes this pull request via Graphite.
• Feb 8, 6:00 PM EST: @tlively merged this pull request with Graphite.