Various fixes related to the -> operator

src/main/scala/millfork/compiler/AbstractStatementPreprocessor.scala

@@ -156,6 +156,9 @@ abstract class AbstractStatementPreprocessor(ctx: CompilationContext, statements
       case ExpressionStatement(expr) =>
         cv = search(expr, cv)
         ExpressionStatement(optimizeExpr(expr, cv)).pos(pos) -> cv
+      case ReturnStatement(Some(expr)) =>
+        cv = search(expr, cv)
+        ReturnStatement(Some(optimizeExpr(expr, cv))).pos(pos) -> cv
       case IfStatement(cond, th, el) =>
         cv = search(cond, cv)
         val c = optimizeExpr(cond, cv)

src/main/scala/millfork/node/opt/UnusedGlobalVariables.scala

@@ -64,6 +64,7 @@ object UnusedGlobalVariables extends NodeOptimization {
     case FunctionCallExpression(name, xs) => name :: getAllReadVariables(xs)
     case IndexedExpression(arr, index) => arr :: getAllReadVariables(List(index))
     case SeparateBytesExpression(h, l) => getAllReadVariables(List(h, l))
+    case IndirectFieldExpression(root, firstIndices, fields) => getAllReadVariables(List(root) ++ firstIndices ++ fields.flatMap(_._2))
     case _ => Nil
   }
 

src/test/scala/millfork/test/PointerSuite.scala

@@ -209,4 +209,26 @@ class PointerSuite extends FunSuite with Matchers with AppendedClues {
       }
     }
   }
+
+  test("Pointers and arrays") {
+    EmuCrossPlatformBenchmarkRun(Cpu.Mos, Cpu.Z80)(
+      """
+        | struct P {
+        |    word i
+        |    byte c
+        |    byte d
+        | }
+        |
+        | array a [sizeof(P)*8]
+        |
+        | noinline byte f(byte i) {
+        |     return pointer.P(a.addr + sizeof(P)*i)->c
+        | }
+        |
+        | void main() {
+        |     f(6)
+        | }
+      """.stripMargin) { m =>
+    }
+  }
 }