SplitTypeParameterCountFromReflectionName allocated the digits after
the backtick only to feed int.TryParse and discard them, and the
TopLevelTypeName constructor cut the name part twice for generic
types (once at the dot, again at the backtick), dropping the first
cut. Both run for every generic reflection name parsed, e.g. for
typeof-valued attribute arguments and string-switch metadata. The
arity is now parsed in place with a digit loop (netstandard2.0 has
no span int.TryParse) and each final string is cut exactly once.
The digit loop only accepts plain ASCII digits, so suffixes like
`+1 that int.TryParse tolerated are now rejected; such names are not
legal reflection names. New unit tests pin the parse edge cases.
Assisted-by: Claude:claude-fable-5:Claude Code
This is a work-in-progress; ILSpy is not functional with this commit.
The old code path still exists but is broken because some classes were modified for the new system.
The new system is still highly incomplete (types only have fields, but no methods).