Relax isPOD rules so ctors don't make structs non-POD
Issue 11503 - immutable return value from pure function implicitly converts to mutable.
Remove CallExp::implicitCastTo altogether.

The pure -> immutable case is checked in implicitConvTo as well,
and since it yields MATCHexact, the castTo() in
Expression::implicitCastTo is a no-op anyway.
Issue 11909 - Struct members and static arrays break pure function escape analysis (immutability violation).
Clarify traverseIndirections implementation.

No functional change intended.
Make traverseIndirections() return bool instead of int.
Disable rtti
Use a different token type for hex strings
Merge pull request #3146 from yebblies/hextoken

[trivial] Use a different token type for hex strings
Merge pull request #3153 from yebblies/nortti

[DDMD] Disable rtti
Use writeByte everywhere instead of having writeByte and writebyte
Call extractString instead of manually null-terminating and extracting
Call extractString instead of toChars and manually NULLing .data
Replace OutBuffer::toChars with peekString to clarify intent and avoid confusion with Object::toChars
Merge pull request #3154 from yebblies/extractstring

[cleanup] Clean up the way strings are created from `OutBuffer`
Explicitly cast off_t to size_t
fix Issue 12002 - Internal error: toir.c 181
Merge pull request #3159 from 9rnsr/fix12002

[REG] Issue 12002 - Internal error: toir.c 181
Merge pull request #3061 from ibuclaw/ctorpod

Relax isPOD rules so ctors don't make structs non-POD
Merge pull request #3085 from klickverbot/pure-return-immutable

pure -> immutable fixes