Openenclave: fmal and tgama math functions

[haitaohuang]

Notice fmal() and tgamma() functions are marked as unsupported in OE. This may cause issues for people porting apps from Intel SGX SDK which has the support. Opening this issue to track and discuss potential solutions

[jhand2]

Thanks @haitaohuang!

A little context for whoever ends up working on this: fmal and tgamma are currently supported functions in musl, but OE does not compile them into oelibc because of insufficient test coverage. tgamma does not have a test in libc-test and the test for fmal is broken.

The options are:

1. Just compile in the functions anyway
2. Add working tests to libc-test (3rd party library) for these functions

[anakrish]

Thanks for the hint Jordan.

[anakrish]

@jhand2 Thanks for implementing the ability to run each libc test individually. Super helpful!