New opAssign unittests in std.array.array
Simplify T* emplace(T)(T* chunk)
tweak trustedMemcpy in emplace
Change messages in emplace to use format
makes to! string to string safe
ctfe unittest for to!string,string
Use documented unittests for `std.traits.isAssignable`.
[Refactor] Remove redundant parantheses in `std.traits.isAssignable` unittest.
Support degenerate bitfields with fields of length 32 and 64 to match documented constraints.
Add unittests for bugs which seem to have been fixed over time.
Merge pull request #1613 from Safety0ff/master

Support degenerate bitfields with fields of length 32 and 64
fix Issue 11165 - std.typecons._d_toObject conflicts with std.signals._d_toObject
Merge pull request #1614 from 9rnsr/fix11165

[REG2.064a] Issue 11165 - std.typecons._d_toObject conflicts with std.signals._d_toObject
Merge pull request #1491 from monarchdodra/toSafe

makes to! string to string `@safe`, `pure` and `CTFE`-able
Merge pull request #1528 from monarchdodra/arrayEmplaceFixup

Fixup unittest following emplace fix
Merge pull request #1552 from monarchdodra/emplaceFixup

Emplace fixup
Fix Issue 11196 - `std.range.zip` fails to compile if range elements aren't default contructable

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=11196
Merge pull request #1619 from denis-sh/fix-Issue-11196

Fix Issue 11196 - `std.range.zip` fails to compile if range elements aren't default contructable
Clarify `isAssignable` documentation. Add private `isRvalueAssignable` and `isLvalueAssignable`.

Previously `isAssignable` worked like `isLvalueAssignable`.

Also add some unittests.
Merge pull request #1597 from denis-sh/fix-`std.traits.isAssignable`

Fix `std.traits.isAssignable`