hypot: Port from amd builtins

v2: Fix whitespace errors

Use only subnormal path.
Passes CTS on carrizo and turks.
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewer: Aaron Watry <awatry@gmail.com>

llvm-svn: 329647
GitOrigin-RevId: 4be03390233986df3c3fbe3a8f2b0d04de06a34a
5 files changed