Validate RISC-V compilation when test-meson-builds.sh is called. The
check will be only performed if appropriate toolchain is present on the
system (same as with other architectures).
Sponsored-by: Frank Zhao <frank.zhao@starfivetech.com>
Sponsored-by: Sam Grove <sam.grove@sifive.com>
Signed-off-by: Stanislaw Kardach <kda@semihalf.com>