Issue 9571 - link error due to using unique ids in anonymous funcliteral

[9rnsr]

http://d.puremagic.com/issues/show_bug.cgi?id=9571

Emit unique-id in local scope for function literals instead of global ones.

[mihails-strasuns]

Just to make sure I got idea behind the fix right - it relies on the fact that mangled name is fully qualified and restarts anonymous "counter" for each new symbol scope?

[9rnsr]

@Dicebot That's right.

[mihails-strasuns]

@9rnsr will it work properly with template mixins? (I could not get same -inline behaviour for them as in snippet so can't check)

[9rnsr]

Each template mixins has independent symbol scope, so it works as expected.

alias Id(alias a) = a;
template Mix()
{
    alias fn = Id!((){ return 0; });
}
mixin Mix!() m1;
mixin Mix!() m2;
pragma(msg, m1.fn.mangleof);  // _D4test2m19__lambda2FNaNbNfZi
pragma(msg, m2.fn.mangleof);  // _D4test2m29__lambda2FNaNbNfZi