Drop code in tsgo-port that references ES5 or <ES2015 (#62670)

Author: jakebailey

src/compiler/binder.ts

@@ -91,7 +91,6 @@ import {
     getContainingClass,
     getEffectiveContainerForJSDocTemplateTag,
     getElementOrPropertyAccessName,
-    getEmitScriptTarget,
     getEnclosingBlockScopeContainer,
     getEnclosingContainer,
     getErrorSpanForNode,
@@ -280,7 +279,6 @@ import {
     QualifiedName,
     removeFileExtension,
     ReturnStatement,
-    ScriptTarget,
     SetAccessorDeclaration,
     setParent,
     setParentRecursive,
@@ -523,7 +521,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
     /* eslint-disable no-var */
     var file: SourceFile;
     var options: CompilerOptions;
-    var languageVersion: ScriptTarget;
     var parent: Node;
     var container: IsContainer | EntityNameExpression;
     var thisParentContainer: IsContainer | EntityNameExpression; // Container one level up
@@ -583,7 +580,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
     function bindSourceFile(f: SourceFile, opts: CompilerOptions) {
         file = f;
         options = opts;
-        languageVersion = getEmitScriptTarget(options);
         inStrictMode = bindInStrictMode(file, opts);
         classifiableNames = new Set();
         symbolCount = 0;
@@ -606,7 +602,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
 
         file = undefined!;
         options = undefined!;
-        languageVersion = undefined!;
         parent = undefined!;
         container = undefined!;
         thisParentContainer = undefined!;
@@ -2673,36 +2668,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
         }
     }
 
-    function getStrictModeBlockScopeFunctionDeclarationMessage(node: Node) {
-        // Provide specialized messages to help the user understand why we think they're in
-        // strict mode.
-        if (getContainingClass(node)) {
-            return Diagnostics.Function_declarations_are_not_allowed_inside_blocks_in_strict_mode_when_targeting_ES5_Class_definitions_are_automatically_in_strict_mode;
-        }
-
-        if (file.externalModuleIndicator) {
-            return Diagnostics.Function_declarations_are_not_allowed_inside_blocks_in_strict_mode_when_targeting_ES5_Modules_are_automatically_in_strict_mode;
-        }
-
-        return Diagnostics.Function_declarations_are_not_allowed_inside_blocks_in_strict_mode_when_targeting_ES5;
-    }
-
-    function checkStrictModeFunctionDeclaration(node: FunctionDeclaration) {
-        if (languageVersion < ScriptTarget.ES2015) {
-            // Report error if function is not top level function declaration
-            if (
-                blockScopeContainer.kind !== SyntaxKind.SourceFile &&
-                blockScopeContainer.kind !== SyntaxKind.ModuleDeclaration &&
-                !isFunctionLikeOrClassStaticBlockDeclaration(blockScopeContainer)
-            ) {
-                // We check first if the name is inside class declaration or class expression; if so give explicit message
-                // otherwise report generic error message.
-                const errorSpan = getErrorSpanForNode(file, node);
-                file.bindDiagnostics.push(createFileDiagnostic(file, errorSpan.start, errorSpan.length, getStrictModeBlockScopeFunctionDeclarationMessage(node)));
-            }
-        }
-    }
-
     function checkStrictModePostfixUnaryExpression(node: PostfixUnaryExpression) {
         // Grammar checking
         // The identifier eval or arguments may not appear as the LeftHandSideExpression of an
@@ -2731,7 +2696,7 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
 
     function checkStrictModeLabeledStatement(node: LabeledStatement) {
         // Grammar checking for labeledStatement
-        if (inStrictMode && getEmitScriptTarget(options) >= ScriptTarget.ES2015) {
+        if (inStrictMode) {
             if (isDeclarationStatement(node.statement) || isVariableStatement(node.statement)) {
                 errorOnFirstToken(node.label, Diagnostics.A_label_is_not_allowed_here);
             }
@@ -3725,7 +3690,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
 
         checkStrictModeFunctionName(node);
         if (inStrictMode) {
-            checkStrictModeFunctionDeclaration(node);
             bindBlockScopedDeclaration(node, SymbolFlags.Function, SymbolFlags.FunctionExcludes);
         }
         else {