No shader-db changes on any Intel platform.

v2: Use a loop to generate patterns.  Suggested by Jason.

v3: Fix a copy-and-paste bug in the extract_[ui] of ishl loop that would
replace an extract_i8 with and extract_u8.  This broke ~180 tests.  This
bug was introduced in v2.

Reviewed-by: Matt Turner <mattst88@gmail.com> [v1]
Reviewed-by: Dylan Baker <dylan@pnwbakers.com> [v2]
Acked-by: Jason Ekstrand <jason@jlekstrand.net> [v2]