These symbols already appear in the common lib/msun/Symbol.map.
Duplicate entries produce an error with LLVM's LLD linker.
Reviewed by: br
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8627
Hardfloat is now default (use riscv64sf as TARGET_ARCH
for softfloat).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D8529