Set environment variable LIBCLANG_DISABLE_CRASH_RECOVERY=1 as possible fix for sbcl crashing.

[jolby]

Reference: https://reviews.llvm.org/D23662

Before setting this environment variable sbcl crashes nearly every time I run claw (as per the warning on the project front page). After setting this, sbcl has successfully run on some fairly large bindings (aw-skia). Note that while libclang has the exported function: clang_toggleCrashRecovery, this is not sufficient because libclang will destructively install its own signal handlers in clang_createIndex unless this environment variable is set.

[borodust]

This is extremely helpful observation! Thank you. I'll try it out and add to docs as soon as I get back to claw. Maybe I'll also just patch libclang, because why not.