expanded ifu coverage including 4 added directed tests and 1 exclusion, expanded fpu coverage including 6 directed tests and 2 multiline exclusions

Created by: SydRiley

4 files were edited

1. src/fpu/fctrl.sv

• Added 2 multiline coverage exclusions to exclude branches that cannot be covered by the rv64gc configuration because it doesn't support floating point half or quad precision

2. src/ifu/decompress.sv

• Added 1 exclusion of a branch that will never be hit in the rv64gc configuration. The branch requires XLEN !> 32 and in rv64gc, XLEN is 64.

3. tests/coverage/ifu.S

• Added 4 tests to cover 4 previously uncovered branches/instructions (c.fsd, c.fldsp, c.fsdsp, an illegal instruction)

4. tests/coverage/fpu.S

• Added 6 directed tests to cover All False branch for 6 different sets of cases.

The ifu and fpu now have full branch coverage. My next step will be improving the conditional coverage.