Remove unnecessary exports (microsoft#22739)

Author: Andy

src/services/textChanges.ts

@@ -134,11 +134,7 @@ namespace ts.textChanges {
         readonly options?: ChangeNodeOptions;
     }
 
-    export function getSeparatorCharacter(separator: Token<SyntaxKind.CommaToken | SyntaxKind.SemicolonToken>) {
-        return tokenToString(separator.kind);
-    }
-
-    export function getAdjustedStartPosition(sourceFile: SourceFile, node: Node, options: ConfigurableStart, position: Position) {
+    function getAdjustedStartPosition(sourceFile: SourceFile, node: Node, options: ConfigurableStart, position: Position) {
         if (options.useNonAdjustedStartPosition) {
             return node.getStart(sourceFile);
         }
@@ -168,7 +164,7 @@ namespace ts.textChanges {
         return getStartPositionOfLine(getLineOfLocalPosition(sourceFile, adjustedStartPosition), sourceFile);
     }
 
-    export function getAdjustedEndPosition(sourceFile: SourceFile, node: Node, options: ConfigurableEnd) {
+    function getAdjustedEndPosition(sourceFile: SourceFile, node: Node, options: ConfigurableEnd) {
         if (options.useNonAdjustedEndPosition || isExpression(node)) {
             return node.getEnd();
         }