ArmPkg/ArmSoftfloatLib: add missing entry points for RVCT

ArmPkg/ArmSoftfloatLib: add missing entry points for RVCT

The RVCT compiler may emit calls to the various __aeabi_c?cmp??
functions, which return their results via the CPU condition flags
C and Z. According to ARM doc IHI 0043D 'Run-time ABI for the ARM
architecture':

    The 3-way comparison functions c*cmple, c*cmpeq and c*rcmple return
    their results in the CPSR Z and C flags. C is clear only if the operands
    are ordered and the first operand is less than the second. Z is set only
    when the operands are ordered and equal.

Add implementations for the double and float variants of the above.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19327 6f19259b-4bc3-4df7-8a09-765794883524