errors: handle V8 warnings in DisallowJavascriptExecutionScope

[Anshikakalpana]

Fixes: #63473

Fix crash when V8 emits warning inside DisallowJavascriptExecutionScope.

When asm.js code is evaluated in the REPL with previews enabled, V8 emits a deprecation warning inside DisallowJavascriptExecutionScope. Node's warning handler tried to call process.emit() which is JS, causing a fatal crash.

Fix:
check can_call_into_js() before calling ProcessEmitWarningGeneric. If JS is not safe, print the warning directly to stderr instead.

[codecov]

Codecov Report

❌ Patch coverage is 14.28571% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.14%. Comparing base (7eab492) to head (3b02778).
⚠️ Report is 195 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_errors.cc	14.28%	5 Missing and 1 partial ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #63486 +/- ##
==========================================
+ Coverage 89.67% 90.14% +0.46% 
==========================================
Files 712 718 +6 Lines 221256 227917 +6661 Branches 42394 42815 +421 ==========================================
+ Hits 198420 205453 +7033 + Misses 14684 14248 -436 - Partials 8152 8216 +64 

Files with missing lines	Coverage Δ
src/node_errors.cc	63.37% <14.28%> (-0.53%)	⬇️

... and 159 files with indirect coverage changes

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[codeCraft-Ritik]

Nice fix! Falling back to stderr when JS execution is disallowed seems like a safe and practical solution.