style: purge em dashes from the produced text

Assisted-by: GLM 5.3 Flash

verify/abi_arm64.s

@@ -9,7 +9,7 @@
 //
 // The return trampoline (leaveJITCheckedRaw) is a raw TEXT symbol with no
 // Go function declaration, so the toolchain does NOT interpose an
-// ABIInternal wrapper — the JIT function RETs directly into the check
+// ABIInternal wrapper; the JIT function RETs directly into the check
 // code, which sees the registers exactly as the function left them.
 //
 // Go ABI on arm64 guarantees:
@@ -48,7 +48,7 @@ TEXT ·enterJITChecked(SB), NOSPLIT, $0-16
 	JMP  (R0)                  // branch to JIT function
 
 // leaveJITCheckedRaw is the raw return trampoline.  It has NO Go function
-// declaration, so no ABIInternal wrapper is generated — the JIT function's
+// declaration, so no ABIInternal wrapper is generated; the JIT function's
 // RET lands here directly, seeing R29 and g exactly as the function left
 // them.  It checks the sentinels, records violations in abiResult, then
 // restores the Go stack and returns.