Import changes

PiperOrigin-RevId: 913030038

snappy-stubs-internal.h

@@ -304,6 +304,7 @@ class Bits {
   void operator=(const Bits&);
 };
 
+// In RISC-V,  CLZ  is supported by instructions from the ZBB bit-manipulation extension.
 #if HAVE_BUILTIN_CTZ
 
 inline int Bits::Log2FloorNonZero(uint32_t n) {
@@ -393,6 +394,7 @@ inline int Bits::FindLSBSetNonZero(uint32_t n) {
 
 #endif  // End portable versions.
 
+// In RISC-V,  CLZ  is supported by instructions from the ZBB bit-manipulation extension.
 #if HAVE_BUILTIN_CTZ
 
 inline int Bits::FindLSBSetNonZero64(uint64_t n) {