We don't have floating-point exception or non-default rounding mode
support for the RISC-V soft-float environment, `feraiseexcept' and
`fesetround' do nothing unless the `__riscv_flen' macro has been set.
Therefore following ISO C language requirements[1] only define macros
for soft float that correspond to actually supported floating-point
environment features, removing failures from GCC testing such as:
FAIL: gcc.dg/torture/fp-int-convert-timode-3.c -O0 execution test
FAIL: gcc.dg/torture/fp-int-convert-timode-4.c -O0 execution test
References:
[1] "Programming languages -- C", ISO/IEC 9899:2023, working draft --
September 3, 2022, Section 7.6 "Floating-point environment <fenv.h>"
Fixes: 7040b2de08 ("Add RISC-V port for libm")
Signed-off-by: Maciej W. Rozycki <macro@embecosm.com>