message: fix(compiler-cli): fix memory leak in program creation
  Saving `oldProgram` in `AngularCompilerProgram` instances is causing a memory leak for unemitted programs.
  It's not actually used so simply not saving it fixes the memory leak.
  Fix
  PR Close
diff: @@ -61,7 +61,7 @@ class AngularCompilerProgram implements Program {
  constructor(
  private rootNames: string[], private options: CompilerOptions, private host: CompilerHost,
  - private oldProgram?: Program) {
  + oldProgram?: Program) {
  const [major, minor] = ts.version.split('.');
  if (Number(major) < 2 || (Number(major) === 2 && Number(minor) < 4)) {
  throw new Error('The Angular Compiler requires TypeScript >= 2.4.');
  