More inline asm register name fixups for LLVM

src/librustc_codegen_llvm/asm.rs

@@ -479,10 +479,13 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'tcx>>)
                         _ => unreachable!(),
                     }
                 } else {
-                    // We use i32 as the type for discarded outputs
-                    's'
+                    // We use i64x2 as the type for discarded outputs
+                    'q'
                 };
                 format!("{{{}{}}}", class, idx)
+            } else if reg == InlineAsmReg::AArch64(AArch64InlineAsmReg::x30) {
+                // LLVM doesn't recognize x30
+                "lr".to_string()
             } else {
                 format!("{{{}}}", reg.name())
             }

src/test/assembly/asm/aarch64-types.rs

@@ -553,3 +553,8 @@ check_reg!(v0_f32x4 f32x4 "s0" "fmov");
 // CHECK: fmov s0, s0
 // CHECK: //NO_APP
 check_reg!(v0_f64x2 f64x2 "s0" "fmov");
+
+// Regression test for #75761
+pub unsafe fn issue_75761() {
+    asm!("", out("v0") _, out("x30") _);
+}