Fix missing modification of jump table in licm

cranelift/filetests/filetests/licm/br-table.clif

@@ -0,0 +1,19 @@
+test compile
+set opt_level=speed_and_size
+target x86_64
+
+function %br_table_opt() {
+    jt0 = jump_table [block1, block2]
+
+    block0:
+        v0 = iconst.i32 1
+        br_table v0, block2, jt0
+
+    block1: 
+        return
+
+    block2:
+        v1 = iconst.i32 1
+        jump block2
+
+}

cranelift/filetests/filetests/licm/rewrite-jump-table.clif

@@ -0,0 +1,28 @@
+test licm
+target aarch64
+
+function %rewrite_jump_table() {
+    jt0 = jump_table [block1, block2]
+
+    block0:
+        v0 = iconst.i64 1
+        v1 = jump_table_base.i64 jt0
+        v2 = jump_table_entry.i64 v0, v1, 4, jt0
+        v3 = iadd v1, v2
+        indirect_jump_table_br v3, jt0
+
+    block1:
+        return
+
+    block2:
+        v4 = bconst.b1 false
+        jump block2
+}
+
+; sameln: function
+; nextln: jt0 = jump_table [block1, block3]
+; check: block3:
+; nextln: v4 = bconst.b1 false
+; nextln: jump block2
+; check: block2:
+; nextln: jump block2