intel/compiler: Don't always require precise lowering of flrp

No changes on any other Intel platforms.

Iron Lake and GM45 had similar results. (Iron Lake shown)
total instructions in shared programs: 8164367 -> 8135551 (-0.35%)
instructions in affected programs: 3271235 -> 3242419 (-0.88%)
helped: 13636
HURT: 90
helped stats (abs) min: 1 max: 30 x̄: 2.13 x̃: 1
helped stats (rel) min: 0.04% max: 10.77% x̄: 1.16% x̃: 0.97%
HURT stats (abs)   min: 1 max: 4 x̄: 1.80 x̃: 2
HURT stats (rel)   min: 0.26% max: 11.11% x̄: 1.76% x̃: 0.78%
95% mean confidence interval for instructions value: -2.13 -2.07
95% mean confidence interval for instructions %-change: -1.16% -1.13%
Instructions are helped.

total cycles in shared programs: 188719974 -> 188586222 (-0.07%)
cycles in affected programs: 70415766 -> 70282014 (-0.19%)
helped: 12563
HURT: 515
helped stats (abs) min: 2 max: 600 x̄: 10.90 x̃: 6
helped stats (rel) min: <.01% max: 5.48% x̄: 0.48% x̃: 0.27%
HURT stats (abs)   min: 2 max: 54 x̄: 6.07 x̃: 4
HURT stats (rel)   min: 0.01% max: 4.48% x̄: 0.24% x̃: 0.08%
95% mean confidence interval for cycles value: -10.56 -9.90
95% mean confidence interval for cycles %-change: -0.47% -0.45%
Cycles are helped.

LOST:   0
GAINED: 13

Reviewed-by: Matt Turner <mattst88@gmail.com>
11 jobs for !428 with review/lower-flrp in 8 minutes and 4 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #285511
debian

00:00:16

 
  Build+Test
passed #285513
meson-clang

00:07:46

passed #285516
meson-clover-llvm

00:03:41

passed #285517
meson-clover-llvm39

00:03:38

passed #285515
meson-main

00:05:58

passed #285512
meson-swr-glvnd

00:05:44

passed #285514
meson-vulkan

00:02:46

passed #285519
scons-llvm

00:05:14

passed #285518
scons-nollvm

00:03:39

passed #285520
scons-swr

00:05:40

passed #285521
scons-win64

00:06:11