This commit renames the `is_target_feature_detected!` macro to have different
names depending on the platform. For example:
* `is_x86_feature_detected!`
* `is_arm_feature_detected!`
* `is_aarch64_feature_detected!`
* `is_powerpc64_feature_detected!`
Each macro already has a platform-specific albeit similar interface. Currently,
though, each macro takes a different set of strings so the hope is that like
with the name of the architecture in the module we can signal the dangers of
using the macro in a platform-agnostic context.
One liberty taken with the macro currently though is to on both the x86 and
x86_64 architectures name the macro `is_x86_feature_detected` rather than also
having an `is_x86_64_feature_detected`. This mirrors, however, how all the
intrinsics are named the same on x86/x86_64.
56af498e9e