This extension allows users to query and specify how the implementation
handles floats. SwiftShader does not allow users to modify floating
point behavior at this time, and its default behavior may be
inconsistent due to operating across several architectures.

Bug: b/171498580
Change-Id: I2926f015bdccad0ca2a4cfae195eeeba09781f07
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49728
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Sean Risser <srisser@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>