Control flow graph for Yul.

test/libyul/yulControlFlowGraph/variables.yul

@@ -0,0 +1,31 @@
+{
+    let x := calldataload(0)
+    let y := calldataload(2)
+
+    x := calldataload(3)
+    y := calldataload(4)
+
+    sstore(x,y)
+}
+// ----
+// digraph CFG {
+// nodesep=0.7;
+// node[shape=box];
+//
+// Entry [label="Entry"];
+// Entry -> Block0;
+// Block0 [label="\
+// calldataload: [ 0x00 ] => [ TMP[calldataload, 0] ]\l\
+// Assignment(x): [ TMP[calldataload, 0] ] => [ x ]\l\
+// calldataload: [ 0x02 ] => [ TMP[calldataload, 0] ]\l\
+// Assignment(y): [ TMP[calldataload, 0] ] => [ y ]\l\
+// calldataload: [ 0x03 ] => [ TMP[calldataload, 0] ]\l\
+// Assignment(x): [ TMP[calldataload, 0] ] => [ x ]\l\
+// calldataload: [ 0x04 ] => [ TMP[calldataload, 0] ]\l\
+// Assignment(y): [ TMP[calldataload, 0] ] => [ y ]\l\
+// sstore: [ y x ] => [ ]\l\
+// "];
+// Block0Exit [label="MainExit"];
+// Block0 -> Block0Exit;
+//
+// }