Add x86 SIMD legalizations for icmp less-than

cranelift/filetests/filetests/isa/x86/simd-comparison-run.clif

@@ -137,3 +137,43 @@ ebb0:
     return v8
 }
 ; run
+
+function %icmp_slt_i32x4() -> b1 {
+ebb0:
+    v0 = vconst.i32x4 [-1 1 1 1]
+    v1 = vconst.i32x4 [1 2 3 4]
+    v2 = icmp slt v0, v1
+    v8 = vall_true v2
+    return v8
+}
+; run
+
+function %icmp_ult_i32x4() -> b1 {
+ebb0:
+    v0 = vconst.i32x4 [1 1 1 1]
+    v1 = vconst.i32x4 [-1 2 3 4] ; -1 = 0xffff... will be greater than 1 when unsigned
+    v2 = icmp ult v0, v1
+    v8 = vall_true v2
+    return v8
+}
+; run
+
+function %icmp_sle_i16x8() -> b1 {
+ebb0:
+    v0 = vconst.i16x8 [-1 -1 0 0 0 0 0 0]
+    v1 = vconst.i16x8 [-1  0 0 0 0 0 0 0]
+    v2 = icmp sle v0, v1
+    v8 = vall_true v2
+    return v8
+}
+; run
+
+function %icmp_ule_i16x8() -> b1 {
+ebb0:
+    v0 = vconst.i16x8 [-1  0 0 0 0 0 0 0]
+    v1 = vconst.i16x8 [-1 -1 0 0 0 0 0 0]
+    v2 = icmp ule v0, v1
+    v8 = vall_true v2
+    return v8
+}
+; run