Upgrade rust/crates/futures-channel to 0.3.16

Test: make
Change-Id: I008978abdafb17fb51be53f621dc38d65737271b
diff --git a/no_atomic_cas.rs b/no_atomic_cas.rs
index 0819af1..4708bf8 100644
--- a/no_atomic_cas.rs
+++ b/no_atomic_cas.rs
@@ -3,6 +3,8 @@
 
 const NO_ATOMIC_CAS_TARGETS: &[&str] = &[
     "avr-unknown-gnu-atmega328",
+    "bpfeb-unknown-none",
+    "bpfel-unknown-none",
     "msp430-none-elf",
     "riscv32i-unknown-none-elf",
     "riscv32imc-unknown-none-elf",