Wrap leading function expression iifes in conditionals

[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:
Resolves #4092

Description

This will make sure that when a function expression life without parentheses (i.e. function(){}()) is the leading expression in a conditional, logical or binary expression and tree-shaking leads to this being wrapped in an expression statement, then the function expression receives additional parentheses.

REPL

[github-actions]

Thank you for your contribution! ❤️

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

npm install rollup/rollup#gh-4092-invalid-iife-conditional

or load it into the REPL:
https://rollupjs.org/repl/?pr=4099

[codecov]

Codecov Report

Merging #4099 (535abc9) into master (ce2592d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4099   +/-   ##
=======================================
  Coverage   98.02%   98.02%           
=======================================
  Files         201      201           
  Lines        7029     7036    +7     
  Branches     2060     2063    +3     
=======================================
+ Hits         6890     6897    +7     
  Misses         66       66           
  Partials       73       73           

Impacted Files	Coverage Δ
src/ast/nodes/BinaryExpression.ts	97.50% <100.00%> (+0.27%)	⬆️
src/ast/nodes/ConditionalExpression.ts	100.00% <100.00%> (ø)
src/ast/nodes/LogicalExpression.ts	100.00% <100.00%> (ø)

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