Incorrect use of several constructs as labels

[gooncreeper]

Zig Version

0.15.0-dev.1021+43fba5ea8

Steps to Reproduce and Observed Behavior

Each of the following declarations should cause ast-check errors due to the corresponding label not being found:

const A = struct {
    a: while (true) // used as container field name
    ({
    	break :a usize;
    }),
};
const b: while (true) // used as an identifier
({
    break :b bool;
}) = false;
extern fn c(d: while (true) // used as an identifier
({
    break :d u64;
})) void;

// The following are not semantically valid, however they
// are valid AST's and therefore affect zig fmt.
const F = *align(.g: { // used as an align
    break :g 10;
}: 0)u8; // (and other bit pointer colons)
const H = [.i: { // used as an array length
    break :i 0;
}]u8;

however they don't. Each IDENTIFIER COLON is treated as both their correct use and as a label. This is not allowed because the language's grammar is specified as a PEG (see the Grammar section of the langref) which is unambiguous on how these are interpreted (each token can only belong to one thing).

They are additionally wrongly formatted by zig fmt due to the same issue (each IDENTIFIER COLON gets duplicated).

Expected Behavior

I except the corresponding errors to be emitted, and for zig fmt to not duplicate the labels.

[gooncreeper]

Also same problem for inline loops,

switch (x) {
    inline for(a) |a| a => a,
}

Its not an inline loop. Its an inline switch case.