Use metrics in the full inliner.

test/libyul/yulOptimizerTests/fullInliner/large_function_multi_use.yul

@@ -0,0 +1,43 @@
+{
+	function f(a) -> b {
+        let x := mload(a)
+        b := sload(x)
+        let c := 3
+        mstore(mul(a, b), mload(x))
+        let y := add(a, x)
+        sstore(y, 10)
+    }
+    let a := mload(2)
+    let a2 := 2
+    // This should not be inlined because it is not a constant
+    let r := f(a)
+    // This should be inlined because it is a constant
+    let t := f(a2)
+}
+// ----
+// fullInliner
+// {
+//     {
+//         let a_1 := mload(2)
+//         let a2 := 2
+//         let r := f(a_1)
+//         let f_a := a2
+//         let f_b
+//         let f_x := mload(f_a)
+//         f_b := sload(f_x)
+//         let f_c := 3
+//         mstore(mul(f_a, f_b), mload(f_x))
+//         let f_y := add(f_a, f_x)
+//         sstore(f_y, 10)
+//         let t := f_b
+//     }
+//     function f(a) -> b
+//     {
+//         let x := mload(a)
+//         b := sload(x)
+//         let c := 3
+//         mstore(mul(a, b), mload(x))
+//         let y := add(a, x)
+//         sstore(y, 10)
+//     }
+// }

test/libyul/yulOptimizerTests/fullInliner/large_function_single_use.yul

@@ -0,0 +1,36 @@
+{
+	function f(a) -> b {
+        let x := mload(a)
+        b := sload(x)
+        let c := 3
+        mstore(mul(a, b), mload(x))
+        let y := add(a, x)
+        sstore(y, 10)
+    }
+    // Single-use functions are always inlined.
+    let r := f(mload(1))
+}
+// ----
+// fullInliner
+// {
+//     {
+//         let f_a := mload(1)
+//         let f_b
+//         let f_x := mload(f_a)
+//         f_b := sload(f_x)
+//         let f_c := 3
+//         mstore(mul(f_a, f_b), mload(f_x))
+//         let f_y := add(f_a, f_x)
+//         sstore(f_y, 10)
+//         let r := f_b
+//     }
+//     function f(a) -> b
+//     {
+//         let x := mload(a)
+//         b := sload(x)
+//         let c := 3
+//         mstore(mul(a, b), mload(x))
+//         let y := add(a, x)
+//         sstore(y, 10)
+//     }
+// }

test/libyul/yulOptimizerTests/fullInliner/recursion.yul

@@ -0,0 +1,18 @@
+{
+	function f(a) {
+		f(1)
+	}
+	f(mload(0))
+}
+// ----
+// fullInliner
+// {
+//     {
+//         let f_a := mload(0)
+//         f(1)
+//     }
+//     function f(a)
+//     {
+//         f(1)
+//     }
+// }