Track next scope id on Environment

Currently we allocate all reactive scopes during a single pass, 
InferReactiveScopeVariables, using a local incrementing number to assign 
ScopeIds. This means we can't easily create additional scopes later since we 
don't know the next available scope id. 

Here we add `Environment.nextScopeId` and use that to synthesize scope ids.

compiler/packages/babel-plugin-react-forget/src/HIR/Environment.ts

@@ -24,10 +24,12 @@ import {
   FunctionType,
   IdentifierId,
   PolyType,
+  ScopeId,
   Type,
   ValueKind,
   makeBlockId,
   makeIdentifierId,
+  makeScopeId,
 } from "./HIR";
 import {
   BuiltInMixedReadonlyId,
@@ -412,6 +414,7 @@ export class Environment {
   #shapes: ShapeRegistry;
   #nextIdentifer: number = 0;
   #nextBlock: number = 0;
+  #nextScope: number = 0;
   config: EnvironmentConfig;
 
   #contextIdentifiers: Set<t.Identifier>;
@@ -460,6 +463,10 @@ export class Environment {
     return makeBlockId(this.#nextBlock++);
   }
 
+  get nextScopeId(): ScopeId {
+    return makeScopeId(this.#nextScope++);
+  }
+
   isContextIdentifier(node: t.Identifier): boolean {
     return this.#contextIdentifiers.has(node);
   }

compiler/packages/babel-plugin-react-forget/src/ReactiveScopes/InferReactiveScopeVariables.ts

@@ -12,7 +12,6 @@ import {
   IdentifierId,
   Instruction,
   makeInstructionId,
-  makeScopeId,
   Place,
   ReactiveScope,
 } from "../HIR/HIR";
@@ -102,7 +101,7 @@ export function inferReactiveScopeVariables(fn: HIRFunction): void {
     let scope = scopes.get(groupIdentifier);
     if (scope === undefined) {
       scope = {
-        id: makeScopeId(scopes.size),
+        id: fn.env.nextScopeId,
         range: identifier.mutableRange,
         dependencies: new Set(),
         declarations: new Map(),