012 branch in override yes

// Test 430_012: Value-level branching (yes-arm) inside a coordinate override.
//
// [template] constructs (std/control:if, cond, for) splice host source text
// and never expand inside impl-of-comptime flows, so a coordinate override
// cannot use `if`. std/compiler:branch takes a bool VALUE through a plain
// proc instead and lowers in every position. This pins the yes-arm.
~import std/compiler
~import std/control

~[comptime] tor always-true {} -> bool

~proc always-true|zig {
    return true;
}

~std/compiler:coordinate = always-true(): t
|> std/compiler:branch(cond: t)
| yes => error "BRANCH-YES"
| no => error "BRANCH-NO"