RFR: JDK-8302801: Remove fdlibm C sources [v3]

[Joe Darcy]

On Fri, 3 Mar 2023 00:38:18 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Actually this is really my lack of understanding about the current code: why do we intrinsify `Math` but not `StrictMath`?

In brief, the Math methods are allowed implementation flexibility in terms of their algorithm but the StrictMath methods are not. The "interesting" StrictMath methods are required to use the FDLIBM algorithms.

(One exception is StrictMath.sqrt. Since sqrt is required to be correctly rounded, there is only one correct answer for any given argument and StrictMath.sqrt can be intrinsified to a hardware sqrt instruction just like Math.sqrt can.)

-------------

PR: https://git.openjdk.org/jdk/pull/12821