Module barriers

Memory barrier bindings.

Reference

NETWORK_IMPL_GUIDE.md §2.2.1, §2.4

Functions

• asm_bar_lfence 🔒 ^⚠
• asm_bar_mfence 🔒 ^⚠
• asm_bar_sfence 🔒 ^⚠
• lfence
  Load fence - ensures all prior loads complete before subsequent.
• mfence
  Full memory fence - ensures all prior loads AND stores complete.
• sfence
  Store fence - ensures all prior stores are globally visible.