Fix tests/assembly/dwarf-mixed-versions-lto.rs test failure on riscv64

Author: CaiWeiran

tests/assembly/dwarf-mixed-versions-lto.rs

@@ -1,6 +1,7 @@
 // This test ensures that if LTO occurs between crates with different DWARF versions, we
 // will choose the highest DWARF version for the final binary. This matches Clang's behavior.
 // Note: `.2byte` directive is used on MIPS.
+// Note: `.half` directive is used on RISC-V.
 
 //@ only-linux
 //@ aux-build:dwarf-mixed-versions-lto-aux.rs
@@ -15,6 +16,6 @@ fn main() {
 }
 
 // CHECK: .section .debug_info
-// CHECK-NOT: {{\.(short|hword|2byte)}} 2
-// CHECK-NOT: {{\.(short|hword|2byte)}} 4
-// CHECK: {{\.(short|hword|2byte)}} 5
+// CHECK-NOT: {{\.(short|hword|2byte|half)}} 2
+// CHECK-NOT: {{\.(short|hword|2byte|half)}} 4
+// CHECK: {{\.(short|hword|2byte|half)}} 5