nim: update to version 1.6.12

Changelog (https://nim-lang.org/blog/2022/11/23/version-1610-released.html,
https://nim-lang.org/blog/2023/03/10/version-1612-released.html):

Version 1.6.12 released

The Nim team is happy to announce version 1.6.12, our sixth patch release for Nim 1.6.

Version 1.6.12 is a result of almost four months of hard work, and it contains 51 commits, bringing some general improvements over 1.6.10.

Bugfixes

These reported issues were fixed:

    Fixed “sizeof object containing a set is wrong” (#20914)
    Fixed “Missing bounds check for len(toOpenArray..)” (#20954)
    Fixed “Add warning for bare except: clause” (#19580)
    Fixed “Little Copyright notice inconsistency” (#20906)
    Fixed “std/deques: wrong result after calling shrink” (#21278)
    Fixed “io.readLine adds ‘\00’ char to the end” (#21273)
    Fixed “New JS mdoe issue: return + ref ints.” (#21317)
    Fixed “Bad codegen for passed var seq to proc returning array[] converted to seq with @” (#21333)
    Fixed “Templates allowed to use ambiguous identifier” (#1027)
    Fixed “Mutating a var parameter through a mutable view triggers SIGSEGV” (#20422)
    Fixed “macOS use SecRandomCopyBytes instead of getentropy” (#20466)
    Fixed “gcc error when constructing an object that has the same name in the same file name in 2 different directories” (#20139)

Version 1.6.10 released

The Nim team is happy to announce version 1.6.10, our fifth patch release for Nim 1.6.

Version 1.6.10 is a result of almost four months of hard work, and it contains 29 commits, bringing some general improvements over 1.6.8.

This version brings OpenSSL 3 support to Nim 1.6, and large allocations and deallocations for ARC/ORC are now faster.

Bugfixes

These reported issues were fixed:

    Fixed “–styleCheck:off does not work (and –styleCheck:hint is now the default?)” (#20397)
    Fixed “dereferencing pointer to incomplete type error with gcc 9.4 with statics/cast” (#20141)
    Fixed “strutils.find uses cstring optimization that stops after \0” (#19500)
    Fixed “Nimpretty mangles numeric literal procs” (#20553)
    Fixed “Regression in proc symbol resolution; Error: attempting to call routine “ (#18990)
    Fixed “of operator doesn’t consider generics under orc/arc” (#20391)
    Fixed ““incompatible type” when mixing float32 and cfloat in generics” (#19349)
    Fixed “cannot generate code for: mSlice with toOpenArray” (#19969)
    Fixed “-mm flag is ignored on latest Nim 1.7.1 be4bd8” (#20426)

(nikita)