Fix clippy and remove remaining capstone reference in x86_64 tests

- Replace capstone test in asm/x86_64/tests.rs with built-in disassembler
- Add clippy allows for vendored disassembler code (erasing_op,
  manual_range_contains, manual_range_patterns, etc.)

Author: tekknolagi

zjit/src/asm/x86_64/tests.rs

@@ -943,24 +943,9 @@ fn test_xor() {
 
 #[test]
 #[cfg(feature = "disasm")]
-fn basic_capstone_usage() -> std::result::Result<(), capstone::Error> {
-    // Test drive Capstone with simple input
-    use capstone::prelude::*;
-    let cs = Capstone::new()
-        .x86()
-        .mode(arch::x86::ArchMode::Mode64)
-        .syntax(arch::x86::ArchSyntax::Intel)
-        .build()?;
-
-    let insns = cs.disasm_all(&[0xCC], 0x1000)?;
-
-    match insns.as_ref() {
-        [insn] => {
-            assert_eq!(Some("int3"), insn.mnemonic());
-            Ok(())
-        }
-        _ => Err(capstone::Error::CustomError(
-            "expected to disassemble to int3",
-        )),
-    }
+fn basic_disasm_usage() {
+    // Test drive built-in disassembler with simple input
+    let (text, len) = crate::disasm_x86_64::disassemble_one(&[0xCC], 0);
+    assert_eq!(text, "int3");
+    assert_eq!(len, 1);
 }

zjit/src/disasm_aarch64.rs

@@ -5,6 +5,8 @@
 // Ported from the Dart SDK's runtime/vm/compiler/assembler/disassembler_arm64.cc
 // to Rust. Pure Rust, no external dependencies.
 
+#![allow(clippy::manual_range_contains, clippy::needless_late_init)]
+
 /// Register names using standard ARM64 convention.
 const CPU_REG_NAMES: [&str; 32] = [
     "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8", "x9", "x10", "x11",

zjit/src/disasm_x86_64.rs

@@ -5,6 +5,10 @@
 // Ported from the Dart SDK's disassembler_x86.cc to Rust.
 // X64 (long mode, 64-bit) only.
 
+#![allow(clippy::manual_range_contains, clippy::identity_op,
+         clippy::unnecessary_cast, clippy::question_mark,
+         clippy::manual_range_patterns, clippy::erasing_op)]
+
 use core::fmt::Write;
 
 // ---------------------------------------------------------------------------