Merge pull request #6660 from ethereum/shortCircuiting

Short circuiting

test/libsolidity/semanticTests/viaYul/short_circuit.sol

@@ -0,0 +1,17 @@
+contract C {
+    function or(uint x) public returns (bool t, uint y) {
+        t = (x == 0 || ((x = 8) > 0));
+        y = x;
+    }
+    function and(uint x) public returns (bool t, uint y) {
+        t = (x == 0 && ((x = 8) > 0));
+        y = x;
+    }
+}
+// ====
+// compileViaYul: true
+// ----
+// or(uint256): 0 -> true, 0
+// and(uint256): 0 -> true, 8
+// or(uint256): 1 -> true, 8
+// and(uint256): 1 -> false, 1