[Support] Remove PowerOf2Floor and ByteSwap_{16,32,64}

[kazu]

Summary

These functions have been deprecated since:

commit b49b429fde3a282664289d7a2155d994085eb232
Author: Kazu Hirata <[e-mail]>
Date:   Sun Feb 12 21:42:07 2023 -0800

[dblaikie]

SGTM

llvm/include/llvm/Support/MathExtras.h

constexpr inline uint64_t NextPowerOf2(uint64_t A) {
   A |= (A >> 2);
   A |= (A >> 4);
   A |= (A >> 8);
   A |= (A >> 16);
   A |= (A >> 32);
   return A + 1;
 }
 
-/// Returns the power of two which is less than or equal to the given value.
-/// Essentially, it is a floor operation across the domain of powers of two.
-LLVM_DEPRECATED("use llvm::bit_floor instead", "llvm::bit_floor")
-inline uint64_t PowerOf2Floor(uint64_t A) {
-  return llvm::bit_floor(A);
-}
-
 /// Returns the power of two which is greater than or equal to the given value.
 /// Essentially, it is a ceil operation across the domain of powers of two.
 inline uint64_t PowerOf2Ceil(uint64_t A) {
   if (!A)
     return 0;
   return NextPowerOf2(A - 1);
 }
 

llvm/include/llvm/Support/SwapByteOrder.h

 #else
 #if !defined(BYTE_ORDER) && !defined(_WIN32)
 #include <machine/endian.h>
 #endif
 #endif
 
 namespace llvm {
 
-/// ByteSwap_16 - This function returns a byte-swapped representation of
-/// the 16-bit argument.
-LLVM_DEPRECATED("use llvm::byteswap instead", "llvm::byteswap")
-inline uint16_t ByteSwap_16(uint16_t value) { return llvm::byteswap(value); }
-
-/// This function returns a byte-swapped representation of the 32-bit argument.
-LLVM_DEPRECATED("use llvm::byteswap instead", "llvm::byteswap")
-inline uint32_t ByteSwap_32(uint32_t value) { return llvm::byteswap(value); }
-
-/// This function returns a byte-swapped representation of the 64-bit argument.
-LLVM_DEPRECATED("use llvm::byteswap instead", "llvm::byteswap")
-inline uint64_t ByteSwap_64(uint64_t value) { return llvm::byteswap(value); }
-
 namespace sys {
 
 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
 constexpr bool IsBigEndianHost = true;
 #else
 constexpr bool IsBigEndianHost = false;
 #endif