Merge pull request #3054 from WalterBright/fix11591

Regression fix Issue 11591 - std.typecons.Tuple -s with classes fails at runtime as associative array keys
Merge pull request #3056 from 9rnsr/fix11844

Issue 11844 - ICE(template.c:6643) Assertion failed: (td->semanticRun != PASSinit)
Merge pull request #3057 from 9rnsr/fix11849

Issue 11849 - Recursive enum causes segfault
Merge pull request #2826 from 9rnsr/fix11553

Issue 11553 - dmd segfault with recursive template
Merge pull request #3069 from 9rnsr/fix11863

[REG2.064] Issue 11863 - std.conv.to!string(int/uint, radix) returns incorrect string