[build] Prepare workerd for explicit libc++ linkage

[KirillTim]

Edgeworker now supplies libc++ through link_extra_libs.
For "rust_" targets it is supplied via "@@//deps:rust_runtime".

Also disable helloworld_compile_test for debug builds, because
it doesn't work with $ORIGIN relative libc++.so RUNPATH.

Release note: None

[ask-bonk]

APIError: Invalid Anthropic API Key

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[ask-bonk]

APIError: Invalid Anthropic API Key

github run

[ask-bonk]

APIError: Invalid Anthropic API Key

github run

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[codspeed-hq]

Merging this PR will improve performance by 11.59%

⚡ 1 improved benchmark
✅ 71 untouched benchmarks
⏩ 129 skipped benchmarks¹

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	simpleStringBody[Response]	25.2 µs	22.6 µs	+11.59%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing ktimofeev/bazel-hiremtic-libcxx (d7c1d6b) with main (de2058f)}

Footnotes

1. 129 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[npaun]

Seems reasonable - would like to discuss the overall motivation for this though.

[fhanau]

Seems reasonable - would like to discuss the overall motivation for this though.

Yeah I think this merits some more discussion before moving forward with this approach – this adds complexity for every binary that doesn't use libc++, we should only do this if there's no better alternative. In particular, I think we can use LD_LIBRARY_PATH to avoid needing this.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.71%. Comparing base (a58db31) to head (9350d1f).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7025   +/-   ##
=======================================
  Coverage   67.71%   67.71%           
=======================================
  Files         458      458           
  Lines      129341   129341           
  Branches    21144    21144           
=======================================
  Hits        87583    87583           
  Misses      28929    28929           
  Partials    12829    12829           

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[fhanau]

Can you explain why this is needed? Add a comment or remove it if no longer needed

[fhanau]

LGTM otherwise