Function startLexicalEnvironment

test/fixtures/snapshot/typescript.js:109776–109793

* Starts a new lexical environment. Any existing hoisted variable or function declarations * are pushed onto a stack, and the related storage variables are reset.

()

         * are pushed onto a stack, and the related storage variables are reset.
         */
        function startLexicalEnvironment() {
            ts.Debug.assert(state > 0 /* TransformationState.Uninitialized */, "Cannot modify the lexical environment during initialization.");
            ts.Debug.assert(state < 2 /* TransformationState.Completed */, "Cannot modify the lexical environment after transformation has completed.");
            ts.Debug.assert(!lexicalEnvironmentSuspended, "Lexical environment is suspended.");
            // Save the current lexical environment. Rather than resizing the array we adjust the
            // stack size variable. This allows us to reuse existing array slots we've
            // already allocated between transformations to avoid allocation and GC overhead during
            // transformation.
            lexicalEnvironmentVariableDeclarationsStack[lexicalEnvironmentStackOffset] = lexicalEnvironmentVariableDeclarations;
            lexicalEnvironmentFunctionDeclarationsStack[lexicalEnvironmentStackOffset] = lexicalEnvironmentFunctionDeclarations;
            lexicalEnvironmentStatementsStack[lexicalEnvironmentStackOffset] = lexicalEnvironmentStatements;
            lexicalEnvironmentFlagsStack[lexicalEnvironmentStackOffset] = lexicalEnvironmentFlags;
            lexicalEnvironmentStackOffset++;
            lexicalEnvironmentVariableDeclarations = undefined;
            lexicalEnvironmentFunctionDeclarations = undefined;
            lexicalEnvironmentStatements = undefined;
            lexicalEnvironmentFlags = 0 /* LexicalEnvironmentFlags.None */;
        }
        /** Suspends the current lexical environment, usually after visiting a parameter list. */
        function suspendLexicalEnvironment() {
            ts.Debug.assert(state > 0 /* TransformationState.Uninitialized */, "Cannot modify the lexical environment during initialization.");