A new method:

func (s*SymbolTable)GetOrInit()SymbolTable {if*s==nil {*s=make(SymbolTable)}return*s}

Operates on theaddress of a symbol table; when calling it on aSymbolTable, usually on a struct field, Go will take the address of whateverSymbolTable it's accessing, allowing this method to mutate it.

This makes it clearer that this operation is amutating one, unsafe for concurrent use; if you need to find all modifiers, you can just look for anyone assigning toSymbolTable or calling this method. (It also means you can find-references on them again.)

In terms of performance, it inlines; godbolt pegs it as two instructions (it probably was before).

In adding this, I've vetted everything that used to use the old methods; the binder is of course fine. The checkerseemed suspect when I was fixing races previously, but it's not, as the modifications are only on merged symbols (which are either clones or transient symbols local to a checker), or were being called onSymbolTable fields on types, which are also local to a checker.