compiler: Machinery to generate vector types

[FabioLuporini]

No description provided.

[codecov]

Codecov Report

Merging #2253 (cdb83e4) into master (fafa58a) will increase coverage by 0.01%.
The diff coverage is 88.33%.

@@            Coverage Diff             @@
##           master    #2253      +/-   ##
==========================================
+ Coverage   86.92%   86.94%   +0.01%     
==========================================
  Files         229      229              
  Lines       41819    41825       +6     
  Branches     7712     7719       +7     
==========================================
+ Hits        36352    36364      +12     
+ Misses       4840     4834       -6     
  Partials      627      627              

Files	Coverage Δ
devito/passes/iet/definitions.py	82.85% <100.00%> (ø)
devito/passes/iet/engine.py	95.28% <100.00%> (+0.09%)	⬆️
devito/types/array.py	94.03% <90.00%> (+1.63%)	⬆️
devito/mpi/routines.py	92.83% <82.85%> (-0.39%)	⬇️

... and 3 files with indirect coverage changes