Re-enable IR caching in Language Server (#10960)

* Re-enable IR caching in Language Server

When an IR loaded from cache is being run through the same passes,
"interesting" errors may happen. We must ensure that IR is not run
through phases that have already done their transformations.

With this change, I'm no longer seeing failures after project startup.

* resetScope is also obsolete

* address PR review

engine/language-server/src/main/scala/org/enso/languageserver/boot/MainModule.scala

@@ -324,7 +324,7 @@ class MainModule(serverConfig: LanguageServerConfig, logLevel: Level) {
     .logLevel(logLevel)
     .strictErrors(false)
     .disableLinting(false)
-    .enableIrCaches(false) // Until #10921 is fixed
+    .enableIrCaches(true)
     .out(stdOut)
     .err(stdErr)
     .in(stdIn)

engine/runtime-compiler/src/main/scala/org/enso/compiler/Compiler.scala

@@ -573,9 +573,8 @@ class Compiler(
           context.updateModule(
             module,
             u => {
-              u.resetScope()
               u.ir(updatedIr)
-              u.compilationStage(CompilationStage.AFTER_PARSING)
+              u.compilationStage(CompilationStage.AFTER_STATIC_PASSES)
             }
           )
         }