Fix live debugger curried function instrumentation

[watson]

What and why?

Fixes a Live Debugger transform bug where curried functions like this could emit invalid JavaScript:

constmake=(dep)=>functionnamed(){returndep;};

Before this fix, the outer arrow instrumentation could overwrite the inner function's closing-brace instrumentation. The generated output effectively looked like this, with the inner try missing its catch/finally:

constmake=(dep)=>{const$dd_p0=$dd_probes('src/utils.ts;make');try{if($dd_p0)$dd_entry($dd_p0,this,{dep});const$dd_rv0=functionnamed(){const$dd_p1=$dd_probes('src/utils.ts;named');try{let$dd_rv1;if($dd_p1)$dd_entry($dd_p1,this);return($dd_rv1=dep,$dd_p1 ? $dd_return($dd_p1,$dd_rv1,this) : $dd_rv1);};if($dd_p0)$dd_return($dd_p0,$dd_rv0,this,{dep});return$dd_rv0;}catch(e){if($dd_p0)$dd_throw($dd_p0,e,this,{dep});throwe;}};

That invalid output fails downstream parsers with errors like Missing catch or finally clause or Expected a semicolon.

How?

The expression-body path now updates the first body character as before, but appends the suffix at bodyEnd instead of rewriting [bodyEnd - 1, bodyEnd]. This keeps the inner block-body postamble intact when the arrow body is another function or arrow.

Added table-driven nested-function regression coverage for named function expressions, exported function-expression factories, triple-nested callback shapes, and curried arrows across namedOnly modes.

[watson]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Add decorator support to Live Debugger instrumentation #448
• Fix Live Debugger parenthesized arrow body instrumentation #447
• Fix Live Debugger returned arrow instrumentation #442
• Fix live debugger curried function instrumentation #441 👈 (View in Graphite)
• Fix Safari dormant overhead in Live Debugger instrumentation #438
• Add Live Debugger runtime benchmark coverage #429: 1 other dependent PR (#440)
• master

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[datadog-datadog-prod-us1]

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