Remove unnecessary, too strict assertion. Fix for 3161.

Assertion was intended for SIMD lowering of F64x2ConvertLowI32x4U

cranelift/codegen/src/isa/x64/lower.rs

@@ -4579,12 +4579,6 @@ fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
                 };
                 let src = put_input_in_reg(ctx, uwiden_input);
                 let dst = get_output_reg(ctx, outputs[0]).only_reg().unwrap();
-                let input_ty = ctx.input_ty(uwiden, 0);
-                let output_ty = ctx.output_ty(insn, 0);
-
-                // Matches_input further obfuscates which Wasm instruction this is ultimately
-                // lowering. Check here that the types are as expected for F64x2ConvertLowI32x4U.
-                debug_assert!(input_ty == types::I32X4 || output_ty == types::F64X2);
 
                 // Algorithm uses unpcklps to help create a float that is equivalent
                 // 0x1.0p52 + double(src). 0x1.0p52 is unique because at this exponent