[REG 2.095] Fix build regression when compiling dmd using separate compilation

[ibuclaw]

• Reverts Moved resolveAliasThis from aliasthis.d to expressionsem.d #11743, as it caused missing template symbols for both dmd.root.stringtable.StringValue!(Type) and core.internal.array.equality.__equals!(Ensure[], Ensure[]) when building the dmd front-end using separate compilation method. Closes Issue 21294, however the underlying cause of templates not being emitted is being worked on by @atilaneves and co.
• Applies an additional special workaround, because there were still undefined references to dmd.root.stringtable.StringValue!(Type) when the host compiler is dmd.

When compiling dmd modules separately, there is still undefined references to the symbol dmd.root.stringtable.StringTable!(Symbol), this can be resolved by adding the following leaf module should it ever become a probem:

module dmd.stringvaluetypes;

import dmd.gluelayer;
import dmd.root.stringtable;

alias SymbolStringValue = StringValue!(Symbol*);

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	21294	regression	[REG 2.095]: DMD fails to link since PR11743

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 "master + dmd#11827"

[ibuclaw]

@thewilsonator ping?
@RazvanN7 / @AsterMiha FYI.

[ibuclaw]

FYI, I'm running dustmite on this to get a reduced test which has missing StringValue!(Type) symbols, this will go into a new issue.

[ibuclaw]

Bugzilla reference for missing template issue that #11743 possibly managed to trigger.
https://issues.dlang.org/show_bug.cgi?id=21299