fix compiler crash when initializing struct var with something other than a struct literal

compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt

@@ -82,6 +82,11 @@ internal class AstIdentifiersChecker(private val program: Program,
                 return super.visit(decl)
             }
 
+            if(decl.value !is StructLiteralValue) {
+                errors.err("requires struct literal value to initialize a struct variable", decl.value?.position ?: decl.position)
+                return super.visit(decl)
+            }
+
             val decls = decl.flattenStructMembers()
             decls.add(decl)
             val result = AnonymousScope(decls, decl.position)

compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt

@@ -118,8 +118,8 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                 assignFromEvalResult(assign.target)
             }
             is ArrayLiteralValue, is StringLiteralValue -> TODO("string/array/struct assignment?")
-            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened")
-            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
+            is StructLiteralValue -> throw AssemblyError("struct literal value assignment should have been flattened ${assign.value.position}")
+            is RangeExpr -> throw AssemblyError("range expression should have been changed into array values ${assign.value.position}")
         }
     }
 

examples/test.p8

@@ -12,8 +12,8 @@ main {
     }
 
     sub start() {
-        ; Color c = [1,2,3]       ; TODO fix compiler error
         Color c = {1,2,3}
+        c= {1,2,3}
     }
 
  }