feat(interface-types) Implement the string.size instruction.

src/encoders/binary.rs

@@ -299,6 +299,8 @@ where
                 0x23_u8.to_bytes(writer)?;
                 (*allocator_index as u64).to_bytes(writer)?;
             }
+
+            Instruction::StringSize => 0x24_u8.to_bytes(writer)?,
         }
 
         Ok(())
@@ -577,9 +579,10 @@ mod tests {
                 Instruction::I64FromU64,
                 Instruction::StringLiftMemory,
                 Instruction::StringLowerMemory { allocator_index: 1 },
+                Instruction::StringSize,
             ],
             &[
-                0x24, // list of 36 items
+                0x25, // list of 37 items
                 0x00, 0x01, // ArgumentGet { index: 1 }
                 0x01, 0x01, // CallCore { function_index: 1 }
                 0x02, // S8FromI32
@@ -616,6 +619,7 @@ mod tests {
                 0x21, // I64FromU64
                 0x22, // StringLiftMemory
                 0x23, 0x01, // StringLowerMemory { allocator_index: 1 }
+                0x24, // StringSize
             ]
         );
     }