Add support for denormalized half-floats

This change introduces support for the conversion of denormalized half floats and improves the conversion of float -> half-float.

In addition, code formatting has been adjusted and all tests were properly verified and updated.

Also, I added a test case to verify that the conversion half-float to float works as expected.

Bug: 155932921
TEST: atest half_test --rerun-until-failure=30
Flag: EXEMPT bug fix
Change-Id: I2bcfb16e64a6e3f8a1cb1685bc93bbfd3910dd0d