Add sanity test to verify floating point std math lib works for BPF (#21013)

On-chain programs frequently require floating point operations. In
addition standard library functions are expected to be available.
This change adds a simple sanity check that such functions are
available and work correctly when compiled to BPF.

programs/bpf/tests/programs.rs

@@ -1400,7 +1400,7 @@ fn assert_instruction_count() {
             ("solana_bpf_rust_noop", 480),
             ("solana_bpf_rust_param_passing", 146),
             ("solana_bpf_rust_rand", 487),
-            ("solana_bpf_rust_sanity", 1716),
+            ("solana_bpf_rust_sanity", 8397),
             ("solana_bpf_rust_secp256k1_recover", 25216),
             ("solana_bpf_rust_sha", 30704),
         ]);