nir/opcodes: Clear variable names confusion

Having Python and C variables sharing name in the same block of code
makes its understanding a bit confusing. Make it explicit that the
Python bit_size variable refers to the destination bit size.

Suggested-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
42 jobs for !2030 with clear-variable-names-confusion in 44 minutes and 35 seconds (queued for 20 seconds)
detached
Status Job ID Name Coverage
  Containers
passed #627547
debian-10

00:00:34

passed #627548
debian-9

00:00:25

passed #627549
aarch64
test-container:arm64

00:00:19

 
  Build
passed #627552
meson-arm64

00:04:22

passed #627551
meson-armhf

00:02:23

passed #627554
meson-clang

00:08:17

passed #627557
meson-clover

00:05:38

passed #627558
meson-clover-old-llvm

00:05:14

passed #627560
meson-i386

00:03:49

passed #627550
meson-main

00:10:51

passed #627553
meson-swr-glvnd

00:05:27

passed #627559
meson-vulkan

00:01:53

passed #627561
scons

00:08:36

passed #627562
scons-old-llvm

00:07:54

passed #627555
scons-swr

00:05:11

passed #627556
scons-win64

00:05:32

 
  Test
passed #628057
db410c
arm64_a306_gles2 1/4

00:04:10

passed #628058
db410c
arm64_a306_gles2 2/4

00:10:36

passed #627585
db410c
arm64_a306_gles2 3/4

00:04:13

passed #627586
db410c
arm64_a306_gles2 4/4

00:04:28

passed #627572
mesa-cheza
arm64_a630_gles2

00:04:46

passed #627573
mesa-cheza
arm64_a630_gles31 1/4

00:06:15

passed #627574
mesa-cheza
arm64_a630_gles31 2/4

00:08:08

passed #627575
mesa-cheza
arm64_a630_gles31 3/4

00:08:14

passed #627576
mesa-cheza
arm64_a630_gles31 4/4

00:07:49

passed #627577
mesa-cheza
arm64_a630_gles3 1/6

00:04:44

passed #627578
mesa-cheza
arm64_a630_gles3 2/6

00:04:45

passed #627579
mesa-cheza
arm64_a630_gles3 3/6

00:04:17

passed #627580
mesa-cheza
arm64_a630_gles3 4/6

00:04:16

passed #627581
mesa-cheza
arm64_a630_gles3 5/6

00:04:16

passed #627582
mesa-cheza
arm64_a630_gles3 6/6

00:04:07

passed #627563
test-llvmpipe-gles2 1/4

00:04:31

passed #627564
test-llvmpipe-gles2 2/4

00:03:53

passed #627565
test-llvmpipe-gles2 3/4

00:03:37

passed #627566
test-llvmpipe-gles2 4/4

00:03:44

passed #627567
test-softpipe-gles2 1/4

00:01:27

passed #627568
test-softpipe-gles2 2/4

00:01:37

passed #627569
test-softpipe-gles2 3/4

00:01:32

passed #627570
test-softpipe-gles2 4/4

00:01:37

passed #627571
test-softpipe-gles3-limited

00:03:53

failed #627583
db410c
arm64_a306_gles2 1/4

00:06:13

failed #627584
db410c
arm64_a306_gles2 2/4

00:05:52