Update StructFloatInfoFlags doc comment on C#

Author: tomeksowi

src/coreclr/tools/Common/JitInterface/CorInfoTypes.cs

@@ -1221,8 +1221,8 @@ public struct SYSTEMV_AMD64_CORINFO_STRUCT_REG_PASSING_DESCRIPTOR
         public byte eightByteOffsets1;
     };
 
-    // StructFloadFieldInfoFlags: used on LoongArch64 architecture by `getLoongArch64PassStructInRegisterFlags` and
-    // `getRISCV64PassStructInRegisterFlags` API to convey struct argument passing information.
+    // StructFloatFieldInfoFlags: used on LoongArch64 and RISC-V architecture as a legacy representation of
+    // FpStructInRegistersInfo, returned by FpStructInRegistersInfo.ToOldFlags()
     //
     // `STRUCT_NO_FLOAT_FIELD` means structs are not passed using the float register(s).
     //