Fix position context of enum/decl literal in if/while/for

[FnControlOption]

For example:

var foo = if (bar) .foo else .bar;
//                 ^^^^

[Techatrix]

This needs to handle for and while loops as well.

[FnControlOption]

Hm… Do you have any example code of loops that have only a decl literal as the body? I know it’s possible to have a break statement with a decl literal, but we already support that 🤔

[Techatrix]

Do you have any example code of loops that have only a decl literal as the body?

None that is semantically valid but that doesn't matter regarding the position context. The token sequence if (expr) . should produce the same position context as while (expr) .. This should also prevent nonsensical code completions like this:

const foo: ?u32 = undefined;
const bar = while (foo) .<request completions here>