x86: add encoding for bnot.b1.

Fixes #1743.

Co-authored-by: iximeow <git@iximeow.net>

cranelift/codegen/meta/src/isa/x86/encodings.rs

@@ -1454,6 +1454,7 @@ fn define_alu(
     // x86 has a bitwise not instruction NOT.
     e.enc_i32_i64(bnot, rec_ur.opcodes(&NOT).rrr(2));
     e.enc_b32_b64(bnot, rec_ur.opcodes(&NOT).rrr(2));
+    e.enc_both(bnot.bind(B1), rec_ur.opcodes(&NOT).rrr(2));
 
     // Also add a `b1` encodings for the logic instructions.
     // TODO: Should this be done with 8-bit instructions? It would improve partial register

cranelift/filetests/filetests/isa/x86/bnot-b1.clif

@@ -0,0 +1,14 @@
+test binemit
+test run
+
+target x86_64
+
+function u0:323() -> b1 {
+block0:
+    [-,%rax] v221 = bconst.b1 false   ; bin: 40 b8 00000000
+    [-,%rcx] v222 = bconst.b1 true    ; bin: 40 b9 00000001
+    [-,%rax] v223 = bnot v221         ; bin: 40 f7 d0
+    [-,%rax] v224 = band v223, v222   ; bin: 40 21 c8
+    return v224
+}
+; run