Fix post bailout hook execution in 8.3 unoptimized builds

[bwoebi]

When optimized, all is fine; however, in unoptimized builds the compiler will write stacktarget back to the stack and read it later from there, even though the stack address has moved. (i.e. only affects development builds.)

Adding register keyword to avoid this.

Description

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.95%. Comparing base (44a07ba) to head (21dd318).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2737      +/-   ##
============================================
- Coverage     79.24%   77.95%   -1.29%     
  Complexity     2216     2216              
============================================
  Files           201      227      +26     
  Lines         22595    26613    +4018     
  Branches          0      988     +988     
============================================
+ Hits          17905    20747    +2842     
- Misses         4690     5340     +650     
- Partials          0      526     +526     

Flag	Coverage Δ
appsec-extension	69.13% <ø> (?)
tracer-extension	78.82% <100.00%> (+<0.01%)	⬆️
tracer-php	80.54% <ø> (+0.69%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
..._abstract_interface/interceptor/php8/interceptor.c	77.42% <100.00%> (+0.05%)	⬆️

... and 32 files with indirect coverage changes

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[pr-commenter]

Benchmarks

Benchmark execution time: 2024-06-28 11:52:07

Comparing candidate commit 21dd318 in PR branch bob/fix-83-posthook with baseline commit 44a07ba in branch master.

Found 0 performance improvements and 4 performance regressions! Performance is the same for 174 metrics, 0 unstable metrics.

scenario:ComposerTelemetryBench/benchTelemetryParsing-opcache

• 🟥 execution_time [+1.845µs; +4.355µs] or [+3.455%; +8.155%]

scenario:EmptyFileBench/benchEmptyFileBaseline

• 🟥 execution_time [+73.634µs; +172.486µs] or [+3.119%; +7.306%]

scenario:EmptyFileBench/benchEmptyFileOverhead

• 🟥 execution_time [+56.849µs; +152.651µs] or [+2.207%; +5.926%]

scenario:LaravelBench/benchLaravelBaseline

• 🟥 execution_time [+73.931µs; +211.029µs] or [+2.974%; +8.490%]