Link libm in the complex-5.c testcase

This appears to be needed on FreeBSD:

ld.lld: error: undefined symbol: scalbnf
>>> referenced by divsc3.c:26 (/Users/alex/cheri/cheribsd/contrib/llvm-project/compiler-rt/lib/builtins/divsc3.c:26)
>>>               divsc3.o:(__divsc3) in archive /Users/alex/cheri/output/sdk/sysroot-riscv64/usr/lib64/libgcc.a
>>> referenced by divsc3.c:27 (/Users/alex/cheri/cheribsd/contrib/llvm-project/compiler-rt/lib/builtins/divsc3.c:27)
>>>               divsc3.o:(__divsc3) in archive /Users/alex/cheri/output/sdk/sysroot-riscv64/usr/lib64/libgcc.a
>>> referenced by divsc3.c:31 (/Users/alex/cheri/cheribsd/contrib/llvm-project/compiler-rt/lib/builtins/divsc3.c:31)
>>>               divsc3.o:(__divsc3) in archive /Users/alex/cheri/output/sdk/sysroot-riscv64/usr/lib64/libgcc.a
>>> referenced 1 more times

Reviewed By: lenary

Differential Revision: https://reviews.llvm.org/D89621
1 file changed