fix crash when using labels in pointerexpression lab+index

compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt

@@ -551,9 +551,16 @@ internal class AsmGen(private val program: Program,
 
     internal fun loadByteFromPointerIntoA(pointervar: IdentifierReference): Pair<Boolean, String> {
         // returns if the pointer is already on the ZP itself or not (in the latter case SCRATCH_W1 is used as intermediary)
+        val target = pointervar.targetStatement(program)
+        when (target) {
+            is Label -> {
+                val sourceName = asmSymbolName(pointervar)
+                out("  lda  $sourceName")
+                return Pair(true, sourceName)
+            }
+            is VarDecl -> {
                 val sourceName = asmVariableName(pointervar)
-        val vardecl = pointervar.targetVarDecl(program)!!
+                val scopedName = target.makeScopedName(target.name)
-        val scopedName = vardecl.makeScopedName(vardecl.name)
                 if (isTargetCpu(CpuType.CPU65c02)) {
                     return if (isZpVar(scopedName)) {
                         // pointervar is already in the zero page, no need to copy
@@ -585,6 +592,9 @@ internal class AsmGen(private val program: Program,
                     }
                 }
             }
+            else -> throw AssemblyError("invalid pointervar")
+        }
+    }
 
     private  fun fixNameSymbols(name: String) = name.replace("<", "prog8_").replace(">", "")     // take care of the autogenerated invalid (anon) label names
 
@@ -1470,6 +1480,14 @@ $label              nop""")
             val ptrAndIndex = pointerViaIndexRegisterPossible(expr)
             if(ptrAndIndex!=null) {
                 val pointervar = ptrAndIndex.first as? IdentifierReference
+                val target = pointervar?.targetStatement(program)
+                when(target) {
+                    is Label -> {
+                        assignExpressionToRegister(ptrAndIndex.second, RegisterOrPair.Y)
+                        out("  lda  ${asmSymbolName(pointervar)},y")
+                        return true
+                    }
+                    is VarDecl, null -> {
                         if(write) {
                             if(pointervar!=null && isZpVar(pointervar)) {
                                 val saveA = evalBytevalueWillClobberA(ptrAndIndex.second)
@@ -1503,6 +1521,9 @@ $label              nop""")
                         }
                         return true
                     }
+                    else -> throw AssemblyError("invalid pointervar")
+                }
+            }
         }
         return false
     }

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

@@ -785,6 +785,7 @@ data class IdentifierReference(val nameInSource: List<String>, override val posi
     override fun inferType(program: Program): InferredTypes.InferredType {
         return when (val targetStmt = targetStatement(program)) {
             is VarDecl -> InferredTypes.knownFor(targetStmt.datatype)
+            is Label -> InferredTypes.InferredType.known(DataType.UWORD)
             else -> InferredTypes.InferredType.unknown()
         }
     }