Use const parameters in mir.format to reduce template bloat

[nordlow]

The important changes are the qualifications of the parameters to the text and print overloads which in essence strips off either const or immutable qualifier from the type(s) A. In calls such as

text(int.init)
text(const(int).init)
text(immutable(int).init)
...

all result in the same template instance of text potentially saving time and space requirements on compilation and binary sizes.

[nordlow]

Ready now.

[codecov-commenter]

Codecov Report

Merging #359 (b23a5be) into master (5b90150) will decrease coverage by 0.00%.
The diff coverage is n/a.

❗ Current head b23a5be differs from pull request most recent head 38aa2fa. Consider uploading reports for the commit 38aa2fa to get more accurate results

@@            Coverage Diff             @@
##           master     #359      +/-   ##
==========================================
- Coverage   92.64%   92.64%   -0.01%     
==========================================
  Files          62       62              
  Lines       15380    15376       -4     
==========================================
- Hits        14249    14245       -4     
  Misses       1131     1131              

Impacted Files	Coverage Δ
source/mir/format.d	94.44% <ø> (-0.08%)	⬇️

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[nordlow]

Ready now, @9il.

[9il]

• format_impl don't need this. It is an internal stuff that can't compile for const and immutable types.
• Functions that accept numeric types should qualify them as const, not inout. Just for simplicity and they almost already do that.
• The remaining part is two variadic functions. What is the difference between marking them inout and const?

[9il]

const inout(V)[inout(K)] - how this works?

[nordlow]

* format_impl don't need this. It is an internal stuff that can't compile for const and immutable types.

I reverted the changes in format_impl and printStaticString.

[nordlow]

* The remaining part is two variadic functions. What is the difference between marking them `inout` and `const`?

I used

string text(string separator = "", Args...)(auto ref const(Args) args)

instead. It fulfills the purpose of reducing template bloat aswell. Note that

string text(string separator = "", Args...)(auto ref const Args args)

fails with a scope error so I scratched that. I'm not sure how that is different but that doesn't matter for this PR.

[nordlow]

Ready now.

[nordlow]

Does text or print make use of toString-members like std.format.format does? If so, using const(Args) inplace of inout(Args) is gonna require those toString-members to be const.

[9il]

Does text or print make use of toString-members like std.format.format does? If so, using const(Args) inplace of inout(Args) is gonna require those toString-members to be const.

Yes. toString members should be const.