x/tools/gopls: improve completion in binary expressions

[muirdm]

When completing in situations like:

if foo == bar || baz<> {
}

We detect the expected type as "bool" since that is the type of "foo == bar". That causes "bool" candidates to dominate the rankings. However, if your intention is to type "baz.blub == 123", bool candidates are counterproductive, and often obscure the candidate you want.

I propose we get rid of the binary operator type inference for || and && so all candidates are easily completable.

/cc @stamblerre

[gopherbot]

Change https://golang.org/cl/246362 mentions this issue: internal/lsp/source: don't prefer bool candidates in bool exprs