merge with dmc updates
fix Issue 11144 - Better diagnostic for typeid symbol
Merge pull request #2590 from 9rnsr/fix11127

[REG2.064a] Issue 11127 - std.range.cycle linker errors
Improve fail_compilation tests by using `TEST_OUTPUT`
fix Issue 11145 - Duplicated deprecation message "use of typedef is deprecated;"
Improve fail_compilation tests by using `TEST_OUTPUT`
fix Issue 11142 - Wrong error message "no size yet for forward reference" for opaque struct
Improve fail_compilation tests by using `TEST_OUTPUT`
fix Issue 11146 - Wrong line number of "identity assignment operator overload is illegal"
Merge pull request #2600 from 9rnsr/fix11144

Issue 11144 - Better diagnostic for typeid symbol
Merge pull request #2599 from WalterBright/merge-with-dmc

merge with dmc updates
Rename "unittest" to "ddocUnittest" since it should only be used with ddoc.
Fixes Issue 10992 - Missing unittests when using getUnittests trait.
Merge pull request #2544 from AndrejMitrovic/Fix10992

Issue 10992 - Missing unittests when using getUnittests trait
fix Issue 11147 - Nested structs in a union are not correctly initialized
Merge pull request #2596 from 9rnsr/fix7892

Issue 7892 - Compiler-generated struct copies can result in errors when ctor is @disable'd
Merge pull request #2602 from 9rnsr/fix11146

Issue 11146 - Wrong line number of "identity assignment operator overload is illegal"
Merge pull request #2598 from 9rnsr/fix11142

Issue 11142 - Wrong error message "no size yet for forward reference" for opaque struct
Merge pull request #2601 from 9rnsr/fix11145

Issue 11145 - Duplicated deprecation message "use of typedef is deprecated;"
Merge pull request #2603 from 9rnsr/fix11147

Issue 11147 - Nested structs in a union are not correctly initialized