3.4.2 Jun-28-21 Add static trampoline support for Linux on x86_64 and ARM64. Add support for Alibaba's CSKY architecture. Add support for Kalray's KVX architecture. Add support for Intel Control-flow Enforcement Technology (CET). Add support for ARM Pointer Authentication (PA). Fix 32-bit PPC regression. Fix MIPS soft-float problem. Enable tmpdir override with the $LIBFFI_TMPDIR environment variable. Enable compatibility with MSVC runtime stack checking. Reject float and small integer argument in ffi_prep_cif_var(). Callers must promote these types themselves.