Add SVFG::fromValue

[gerion0]

This basically reverts the removal. See #492.

[codecov[bot]]

Codecov Report

Merging #906 (e3be025) into master (3d54728) will decrease coverage by 0.04%. The diff coverage is 0.00%.

:exclamation: Current head e3be025 differs from pull request most recent head d3ade0c. Consider uploading reports for the commit d3ade0c to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #906      +/-   ##
==========================================
- Coverage   63.82%   63.78%   -0.04%     
==========================================
  Files         219      219              
  Lines       22193    22206      +13     
==========================================
  Hits        14165    14165              
- Misses       8028     8041      +13     

Impacted Files	Coverage Δ
include/Graphs/SVFG.h	75.94% <ø> (ø)
lib/Graphs/SVFG.cpp	73.22% <0.00%> (-1.41%)	:arrow_down:

... and 1 file with indirect coverage changes