Roll back parameter default tree shaking

[lukastaegert]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:
See comments at #4518

Description

Considering the unprecedented amount of small bugs that the parameter default tree-shaking has caused, I decided to roll back the feature indefinitely for now. The problem is that for this feature to work correctly, we need to be 100% sure that for every function, we can either track 100% of the calls or if not, deoptimize it. The latter has turned out to become the literal whack-a-mole, causing me to inject so much special logic into the feature that IMO is in no relation to its value. I kept all the regression tests (quite a few!) created for the feature in case I ever attempt it again after some major changes in the call tracking logic.

Sorry to everyone who was looking forward to this 😔

[github-actions]

Thank you for your contribution! ❤️

You can try out this pull request locally by installing Rollup via

npm install rollup/rollup#roll-back-parameter-default-tree-shaking

or load it into the REPL:
https://rollupjs.org/repl/?pr=4520

[codecov]

Codecov Report

Merging #4520 (ecf1612) into master (696ebd3) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4520      +/-   ##
==========================================
- Coverage   98.77%   98.76%   -0.01%     
==========================================
  Files         209      209              
  Lines        7436     7395      -41     
  Branches     2130     2108      -22     
==========================================
- Hits         7345     7304      -41     
  Misses         32       32              
  Partials       59       59              

Impacted Files	Coverage Δ
src/ast/nodes/ArrayExpression.ts	100.00% <ø> (ø)
src/ast/nodes/FunctionDeclaration.ts	100.00% <ø> (ø)
src/ast/nodes/Identifier.ts	98.68% <ø> (-0.02%)	⬇️
src/ast/nodes/ObjectExpression.ts	100.00% <ø> (ø)
src/ast/nodes/shared/ClassNode.ts	100.00% <ø> (ø)
src/ast/nodes/shared/Expression.ts	100.00% <ø> (ø)
src/ast/variables/LocalVariable.ts	93.15% <ø> (+1.25%)	⬆️
src/ast/nodes/ArrowFunctionExpression.ts	94.44% <100.00%> (+1.58%)	⬆️
src/ast/nodes/AssignmentPattern.ts	88.88% <100.00%> (-11.12%)	⬇️
src/ast/nodes/CallExpression.ts	100.00% <100.00%> (ø)
... and 5 more

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