Move the TestCodeSink functionality to MachBufferFinalized

cranelift/codegen/src/isa/arm32/inst/emit_tests.rs

@@ -1,5 +1,4 @@
 use crate::isa::arm32::inst::*;
-use crate::isa::test_utils;
 use crate::settings;
 
 use alloc::vec::Vec;
@@ -1948,12 +1947,10 @@ fn test_arm32_emit() {
         // Check the printed text is as expected.
         let actual_printing = insn.show_rru(Some(&rru));
         assert_eq!(expected_printing, actual_printing);
-        let mut sink = test_utils::TestCodeSink::new();
         let mut buffer = MachBuffer::new();
         insn.emit(&mut buffer, &flags, &mut Default::default());
         let buffer = buffer.finish();
-        buffer.emit(&mut sink);
-        let actual_encoding = &sink.stringify();
+        let actual_encoding = &buffer.stringify_code_bytes();
         assert_eq!(expected_encoding, actual_encoding, "{}", expected_printing);
     }
 }