Fix issue 22549 - float literal should support leading zero

[dkorpel]

Defer errors about digits >= base to after Ldone:.
This way they won't appear when the Lreal: branch is taken.

This also allows such literals for D, since the grammar allows it: https://issues.dlang.org/show_bug.cgi?id=3251

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	22549	normal	importC: float literal should support leading zero

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "stable + dmd#13371"

[dkorpel]

src/core/sync/mutex.d(192): Error: unrecognized trait initSymbol

Is it compiling druntime on master with dmd from stable?

[MoonlightSentinel]

Usually a race condition between force push + base branch change

[dkorpel]

Force pushed because semaphoreci was stuck again

[RazvanN7]

I think that a rebase will fix the macOS failures.

[WalterBright]

I like this fix. Nice!