Respect propertyReadSideEffects in spread elements

[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:
#4113

Description

In #4113, we introduced a check for property access side effects when using spread operators. This check was always applied. This PR changes this by respecting treeshake.propertyReadSideEffects: false.

[github-actions]

Thank you for your contribution! ❤️

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

npm install rollup/rollup#ignore-spread-element-effect

or load it into the REPL:
https://rollupjs.org/repl/?pr=4119

[codecov]

Codecov Report

Merging #4119 (10148c6) into master (b3d130b) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4119   +/-   ##
=======================================
  Coverage   98.11%   98.11%           
=======================================
  Files         201      201           
  Lines        7066     7068    +2     
  Branches     2066     2067    +1     
=======================================
+ Hits         6933     6935    +2     
  Misses         64       64           
  Partials       69       69           

Impacted Files	Coverage Δ
src/ast/nodes/SpreadElement.ts	100.00% <100.00%> (ø)

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