fix(typescript-estree): don't use typescript's synthetic default

[bradzacher]

Fixes #1153

[typescript-eslint]

Thanks for the PR, @bradzacher!

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[codecov]

Codecov Report

Merging #1156 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #1156   +/-   ##
=======================================
  Coverage   94.04%   94.04%           
=======================================
  Files         120      120           
  Lines        5220     5220           
  Branches     1445     1445           
=======================================
  Hits         4909     4909           
  Misses        177      177           
  Partials      134      134

Impacted Files	Coverage Δ
...estree/src/create-program/createIsolatedProgram.ts	73.91% <100%> (ø)	⬆️
...-estree/src/create-program/createDefaultProgram.ts	76.19% <100%> (ø)	⬆️
...pt-estree/src/create-program/createWatchProgram.ts	93.29% <100%> (ø)	⬆️
...ges/typescript-estree/src/create-program/shared.ts	75% <100%> (ø)	⬆️
...ript-estree/src/create-program/createSourceFile.ts	100% <100%> (ø)	⬆️