We can avoid calling transcendental functions by manipulating the
IEEE-754 representation of the single-precision floating point values.

This implementation produces results identical to the reference code.

Bug: b/138944025
Change-Id: I95faf7e80d0604be115dd1b8dfec72f3b8ece841
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/34748
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>