Fix type errors for destructuring assignments(#4227)

[MarckK]

Q	A
Patch: Bug Fix?	yes
Major: Breaking Change?
Minor: New Feature?
Deprecations?
Spec Compliancy?
Tests Added/Pass?
Fixed Tickets	Fixes #4227
License	MIT
Doc PR
Dependency Changes

[MarckK]

Help welcome.
Needs test.

[codecov]

Codecov Report

Merging #5865 into 7.0 will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              7.0    #5865   +/-   ##
=======================================
  Coverage   85.25%   85.25%           
=======================================
  Files         284      284           
  Lines        9963     9963           
  Branches     2781     2781           
=======================================
  Hits         8494     8494           
  Misses        969      969           
  Partials      500      500

Impacted Files	Coverage Δ
packages/babel-types/src/definitions/es2015.js	96.66% <ø> (ø)	⬆️

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[hzoo]

Can do the tests in another PR (or figure out how to test this part of the code in general) 😄 !