Remove delayed typo expressions (#143423)

This removes the delayed typo correction functionality from Clang
(regular typo correction still remains) due to fragility of the
solution.

An RFC was posted here:
https://discourse.llvm.org/t/rfc-removing-support-for-delayed-typo-correction/86631
and while that RFC was asking for folks to consider stepping up to be
maintainers, and we did have a few new contributors show some interest,
experiments show that it's likely worth it to remove this functionality
entirely and focus efforts on improving regular typo correction.

This removal fixes ~20 open issues (quite possibly more), improves
compile time performance by roughly .3-.4%
(https://llvm-compile-time-tracker.com/?config=Overview&stat=instructions%3Au&remote=AaronBallman&sortBy=date),
and does not appear to regress diagnostic behavior in a way we wouldn't
find acceptable.

Fixes #142457
Fixes #139913
Fixes #138850
Fixes #137867
Fixes #137860
Fixes #107840
Fixes #93308
Fixes #69470
Fixes #59391
Fixes #58172
Fixes #46215
Fixes #45915
Fixes #45891
Fixes #44490
Fixes #36703
Fixes #32903
Fixes #23312
Fixes #69874

clang-tools-extra/clangd/unittests/HoverTests.cpp

@@ -974,7 +974,7 @@ class Foo final {})cpp";
          HI.Name = "abc";
          HI.Kind = index::SymbolKind::Variable;
          HI.NamespaceScope = "";
-         HI.Definition = "int abc = <recovery - expr>()";
+         HI.Definition = "int abc";
          HI.Type = "int";
          HI.AccessSpecifier = "public";
        }},