glsl: split DIV_TO_MUL_RCP into single- and double-precision flags

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Tested-by: Glenn Kennard <glenn.kennard@gmail.com>
Tested-by: James Harvey <lothmordor@gmail.com>
Cc: 17.0 <mesa-stable@lists.freedesktop.org>
(cherry picked from commit b71c415c3d288da4b5f533ece42f50f4f20a8c33)
2 files changed