compiler: declare symbols before store so that symbol graph works

bir/src/main/kotlin/gay/pizza/pork/bir/IrDeclare.kt

@@ -0,0 +1,10 @@
+package gay.pizza.pork.bir
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class IrDeclare(override val symbol: IrSymbol, val value: IrCodeElement) : IrCodeElement, IrSymbolOwner {
+  override fun crawl(block: (IrElement) -> Unit) {
+    value.crawl(block)
+  }
+}

bir/src/main/kotlin/gay/pizza/pork/bir/IrVisitor.kt

@@ -29,6 +29,7 @@ interface IrVisitor<T> {
   fun visitIrFunctionArgument(ir: IrFunctionArgument): T
   fun visitIrIndex(ir: IrIndex): T
   fun visitIrListSize(ir: IrListSize): T
+  fun visitIrDeclare(ir: IrDeclare): T
 
   fun visit(ir: IrElement): T = when (ir) {
     is IrBreak -> visitIrBeak(ir)
@@ -59,5 +60,6 @@ interface IrVisitor<T> {
     is IrFunctionArgument -> visitIrFunctionArgument(ir)
     is IrIndex -> visitIrIndex(ir)
     is IrListSize -> visitIrListSize(ir)
+    is IrDeclare -> visitIrDeclare(ir)
   }
 }

compiler/src/main/kotlin/gay/pizza/pork/compiler/IrCodeEmitter.kt

@@ -241,7 +241,7 @@ class IrCodeEmitter(
 
   override fun visitLetAssignment(node: LetAssignment): IrCodeElement {
     val symbol = createLocalVariable(node.symbol)
-    return IrStore(symbol, node.value.visit(this))
+    return IrDeclare(symbol, node.value.visit(this))
   }
 
   override fun visitListLiteral(node: ListLiteral): IrCodeElement =
@@ -296,7 +296,7 @@ class IrCodeEmitter(
 
   override fun visitVarAssignment(node: VarAssignment): IrCodeElement {
     val local = createLocalVariable(node.symbol)
-    return IrStore(local, node.value.visit(this))
+    return IrDeclare(local, node.value.visit(this))
   }
 
   override fun visitWhile(node: While): IrCodeElement = loop { symbol ->

compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt

@@ -188,6 +188,12 @@ class IrStubOpEmitter(val irDefinition: IrDefinition, val code: CodeBuilder) : I
     code.emit(Opcode.Return)
   }
 
+  override fun visitIrDeclare(ir: IrDeclare) {
+    visit(ir.value)
+    val variable = code.localState.createOrFindLocal(ir.symbol)
+    store(variable)
+  }
+
   override fun visitIrStore(ir: IrStore) {
     visit(ir.value)
     val variable = code.localState.createOrFindLocal(ir.target)