Use andn for band_not when bmi1 is present (#5701)

We can use the andn instruction for the lowering of band_not on x64 when bmi1 is available.

cranelift/filetests/filetests/isa/x64/band_not_bmi1.clif

@@ -0,0 +1,17 @@
+test compile precise-output
+target x86_64 has_bmi1
+
+function %f1(i8, i8) -> i8 {
+block0(v0: i8, v1: i8):
+    v2 = band_not v0, v1
+    return v2
+}
+
+;   pushq   %rbp
+;   movq    %rsp, %rbp
+; block0:
+;   andn    %eax, %esi, %edi
+;   movq    %rbp, %rsp
+;   popq    %rbp
+;   ret
+