added vfctprintf() support

[bart112233]

No description provided.

[codecov-commenter]

Codecov Report

Merging #83 into master will decrease coverage by 1.10%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##            master      #83      +/-   ##
===========================================
- Coverage   100.00%   98.89%   -1.11%     
===========================================
  Files            1        1              
  Lines          359      363       +4     
===========================================
  Hits           359      359              
- Misses           0        4       +4     

Impacted Files	Coverage Δ
printf.c	98.89% <0.00%> (-1.11%)	⬇️

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[JakeSays]

I think the name for this function should be fctvprintf to match fctprintf.

[bart112233]

I think the name for this function should be fctvprintf to match fctprintf.

Sure, my mistake

[eyalroz]

This is missing testcase coverage. I'll see if I can take care of that in my fork of the repo.