fix Issue 12604 - No "mismatched array lengths" error with narrowing conversions
fix Issue 12593 - AA cannot have struct as key
fix Issue 12602 - [CTFE] Changes to an array slice wrapped in a struct do not propogate to the original
fix Issue 11535 - CTFE ICE on reassigning a static array initialized with block assignment
fix Issue 12110 - [CTFE] Error: CTFE internal error: Dotvar assignment
Merge pull request #3475 from 9rnsr/fix12604

Issue 12604 - No "mismatched array lengths" error with narrowing conversions
Merge pull request #3480 from 9rnsr/fix12110

Issue 12110 - [CTFE] Error: CTFE internal error: Dotvar assignment
Merge pull request #3479 from 9rnsr/fix11535

Issue 11535 - CTFE ICE on reassigning a static array initialized with block assignment
Merge pull request #3478 from 9rnsr/fix12602

Issue 12602 - [CTFE] Changes to an array slice wrapped in a struct do not propogate to the original
Do not mark mutable parameters as STCin for internal library calls
Merge pull request #3481 from ibuclaw/stcin

Do not mark mutable parameters as STCin for internal library calls
Merge pull request #3476 from 9rnsr/fix12593

[REG2.065] Issue 12593 - AA cannot have struct as key
use const data segments for Mach-O

- add __DATA,__const section as CDATAREL for
  const data with relocations
use CDATA for strings on x86_64

- not sure why it was disabled

- also remove similar old code in elfobj.c
fix for code->cdata relocation

- The codegen assumes an indirect access to data,
  but cdata was treated as code segment so a direct
  relocation was emitted.
fix Issue 9245 - [CTFE] postblit not called on static array initialization

On element-wise or block assignment, currently postblit call is implicitly
handled by glue-layer. Therefore, interpreter should have its own postblit
handling.
Fix Issue 10285 - Enum member with a type but no identifier should not be allowed.
fix Issue 12554 - [ICE](struct.c line 898) with failed delegate purity
add semantics for @nogc
Merge pull request #3490 from WalterBright/more-nogc

DIP60: add semantics for @nogc