Merge branch '2.4.x'

Merge branch '2.4.x'

* 2.4.x:
  progs/cc-progress.c: Use `fstat' to discover the file size.
  math/mpx-mul4-amd64-sse2.S: Always collect iteration count as 32 bits.
  math/mpx-mul4-amd64-sse2.S: Fix stack-argument offset for 64-bit Windows.
  symm/salsa20-x86ish-sse2.S: Fix typo in 64-bit Windows code.
  symm/desx.c, symm/desx.h (desx_init): Fix documentation.
  symm/t/rijndael256: Add tests for small key sizes.
  progs/cc-kem.c (getkem): Parse the `kdf' spec after bulk crypto.
  progs/..., symm/...: Fix 32-bit right-shift idiom.