prog_to_nir, tgsi_to_nir: make sure kill doesn't discard NaNs

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
22 jobs for !1931 with nir-kil in 58 minutes and 48 seconds (queued for 21 seconds)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #593819
debian

00:00:26

 
  Build+Test
passed #593828
meson-arm64

00:02:58

passed #593827
meson-armhf

00:02:25

passed #593822
meson-clang

00:08:38

passed #593825
meson-clover

00:09:43

passed #593829
meson-i386

00:03:36

passed #593820
meson-main

00:11:37

passed #593821
meson-swr-glvnd

00:05:55

passed #593826
meson-vulkan

00:02:45

passed #593831
scons-llvm

00:05:59

passed #593830
scons-nollvm

00:04:26

passed #593823
scons-swr

00:09:53

passed #593824
scons-win64

00:09:53

 
  Test
passed #593832
test-llvmpipe-gles2 1/4

00:04:10

passed #593833
test-llvmpipe-gles2 2/4

00:04:19

passed #593834
test-llvmpipe-gles2 3/4

00:03:51

passed #593835
test-llvmpipe-gles2 4/4

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passed #593836
test-softpipe-gles2 1/4

00:02:03

passed #593837
test-softpipe-gles2 2/4

00:01:53

passed #593838
test-softpipe-gles2 3/4

00:01:24

passed #593839
test-softpipe-gles2 4/4

00:01:34

passed #593840
test-softpipe-gles3-limited

00:04:22