qf1001: handle expressions that have no type

Closes: dominikhgh-1484
Closes: dominikhgh-1510

quickfix/qf1001/qf1001.go

@@ -40,10 +40,12 @@ func CheckDeMorgan(pass *analysis.Pass) (interface{}, error) {
 		found := false
 		ast.Inspect(expr, func(node ast.Node) bool {
 			if expr, ok := node.(ast.Expr); ok {
-				if basic, ok := pass.TypesInfo.TypeOf(expr).Underlying().(*types.Basic); ok {
-					if (basic.Info() & types.IsFloat) != 0 {
-						found = true
-						return false
+				if typ := pass.TypesInfo.TypeOf(expr); typ != nil {
+					if basic, ok := typ.Underlying().(*types.Basic); ok {
+						if (basic.Info() & types.IsFloat) != 0 {
+							found = true
+							return false
+						}
 					}
 				}
 			}

quickfix/qf1001/testdata/src/example.com/CheckDeMorgan/kvexpr.go

@@ -0,0 +1,11 @@
+package pkg
+
+func do() bool {
+	type Info struct {
+		idx int
+	}
+
+	var state map[Info]int
+	// Don't crash on KeyValueExpr
+	return !(state[Info{idx: 6}] == 6 || false) //@ diag(`could apply De Morgan's law`)
+}

quickfix/qf1001/testdata/src/example.com/CheckDeMorgan/kvexpr.go.golden

@@ -0,0 +1,12 @@
+-- Apply De Morgan's law --
+package pkg
+
+func do() bool {
+	type Info struct {
+		idx int
+	}
+
+	var state map[Info]int
+	// Don't crash on KeyValueExpr
+	return state[Info{idx: 6}] != 6 && !false //@ diag(`could apply De Morgan's law`)
+}