Remove special handling of delete aa[key].

This has been an error for a couple of years, and has been deprecated since pre D 1.0.
Deprecate old attribute syntax
Merge pull request #3930 from yebblies/oldattributes

Deprecate old attribute syntax
Merge pull request #3913 from yebblies/deleteaa

Remove special handling of `delete aa[key]`.
fix Issue 13379 - Latest dmd fails with recursive template expansion in std.regex
fix Issue 13394 - invariant fail to link since 2.066 when using separate compilation
Merge pull request #3905 from 9rnsr/fix13379

[REG2.067a] Issue 13379 - Latest dmd fails with recursive template expansion in std.regex
Merge pull request #3918 from 9rnsr/fix13394

[REG2.066] Issue 13394 - invariant fail to link since 2.066 when using separate compilation
+Remove inferred attributes from link symbol names
+stop semanticTypeInfo
+broken tests
+changed test result
+link11395.d
Avoid conservative TypeInfo generation of non-root symbol
fix link11395 and link12144.d
+clean
Remove workaround for issue 13394