fix address-of identifier alias replacement stripping array index away

compiler/test/TestPointers.kt

@@ -7,10 +7,7 @@ import io.kotest.matchers.shouldBe
 import io.kotest.matchers.shouldNotBe
 import io.kotest.matchers.string.shouldContain
 import io.kotest.matchers.types.instanceOf
-import prog8.ast.expressions.AddressOf
-import prog8.ast.expressions.ArrayIndexedExpression
-import prog8.ast.expressions.DirectMemoryRead
-import prog8.ast.expressions.PtrDereference
+import prog8.ast.expressions.*
 import prog8.ast.statements.*
 import prog8.code.ast.*
 import prog8.code.core.BaseDataType
@@ -659,6 +656,44 @@ main {
         compileText(VMTarget(), false, src, outputDir) shouldNotBe null
     }
 
+    test("address-of pointer arithmetic on alias") {
+        val src="""
+main {
+    sub start() {
+        ubyte @shared index = 3
+        ubyte[10] array
+        alias curframe = array
+
+        cx16.r0 = &curframe
+        cx16.r1 = &curframe[3]
+        cx16.r2 = &curframe + 3
+        cx16.r3 = &curframe[index]
+        cx16.r4 = &curframe + index
+    }
+}"""
+        val result = compileText(VMTarget(), false, src, outputDir)!!
+        val st = result.compilerAst.entrypoint.statements
+        st.size shouldBe 9
+        (st[3] as Assignment).value shouldBe instanceOf<AddressOf>()
+        val a1v = (st[4] as Assignment).value as AddressOf
+        a1v.identifier?.nameInSource shouldBe listOf("array")
+        a1v.arrayIndex?.indexExpr?.constValue(result.compilerAst)?.number shouldBe 3.0
+
+        val a2v = (st[5] as Assignment).value as BinaryExpression
+        a2v.left shouldBe instanceOf<AddressOf>()
+        a2v.operator shouldBe "+"
+        (a2v.right as NumericLiteral).number shouldBe 3.0
+
+        val a3v = (st[6] as Assignment).value as AddressOf
+        a3v.identifier?.nameInSource shouldBe listOf("array")
+        (a3v.arrayIndex?.indexExpr as IdentifierReference).nameInSource shouldBe listOf("index")
+
+        val a4v = (st[7] as Assignment).value as BinaryExpression
+        a4v.left shouldBe instanceOf<AddressOf>()
+        a4v.operator shouldBe "+"
+        (a4v.right as TypecastExpression).expression shouldBe instanceOf<IdentifierReference>()
+    }
+
     test("uword struct field array indexing") {
         val src="""
 main {

compilerAst/src/prog8/ast/expressions/AstExpressions.kt

@@ -520,12 +520,10 @@ data class AddressOf(var identifier: IdentifierReference?, var arrayIndex: Array
             node===identifier -> {
                 if(replacement is IdentifierReference) {
                     identifier = replacement
-                    arrayIndex = null
                     dereference = null
                 } else {
                     dereference = replacement as PtrDereference
                     identifier = null
-                    arrayIndex = null
                 }
             }
             node===arrayIndex -> {

examples/test.p8

@@ -1,27 +1,31 @@
-%option enable_floats
-%import textio
-%zeropage basicsafe
 %option no_sysinit
+%zeropage basicsafe
+%import textio
 
 main {
-
-    float f
-
     sub start() {
-        txt.print("classic float pointer+1: ")
-        txt.print_uwhex(&f, true)
-        txt.spc()
-        txt.print_uwhex(&f + 1, true)
-        txt.spc()
-        txt.print_uw(&f + 1 - &f)
-        txt.nl()
+        ubyte @shared index = 3
+        ubyte[10] array
+        alias curframe = array
 
-        txt.print("typed float pointer+1: ")
-        txt.print_uwhex(&&f, true)
+        cx16.r0 = &curframe
+        cx16.r1 = &curframe[3]
+        cx16.r2 = &curframe + 3
+        cx16.r3 = &curframe[index]
+        cx16.r4 = &curframe + index
+
+        txt.print_uw(cx16.r0)
+        txt.nl()
+        txt.print_uw(cx16.r1)
         txt.spc()
-        txt.print_uwhex(&&f + 1, true)
+        txt.print_uw(cx16.r2)
+        txt.nl()
+        txt.print_uw(cx16.r3)
         txt.spc()
-        txt.print_uw(&&f + 1 - &&f)
+        txt.print_uw(cx16.r4)
         txt.nl()
     }
 }
+
+; code sizes on 11.5:  6502: $20a  virt: 140 instr
+; code sizes on 12.0:  6502: ????  virt: ??? instr  (BORKED!)