- Fixed how logarithm2() handles infinity
- Fixed a typo in exponential()

These fixes combined fix all dEQP failures for:
sinh, cosh, pow, exp, log, log2

Change-Id: I2d427892032fc5f75909a5609f606a787b08505a
Reviewed-on: https://swiftshader-review.googlesource.com/13708Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>