mono_patch_info_hash: handle the MONO_PATCH_INFO_OBJC_SELECTOR_REF case
Less cascading errors
Don't resolve extension method expression when in probing mode it may fail to resolve. Fixes #14384
[runtime] Handle MONO_PATCH_INFO_OBJC_SELECTOR_REF in mono_patch_info_hash ().
Revert "[runtime] Handle MONO_PATCH_INFO_OBJC_SELECTOR_REF in mono_patch_info_hash ()."

This reverts commit 924e2b28ced4c78bd76683e44099794ac9045e5b.

Revert this, its not needed.
Optimize MonoCustomAttrs.GetCustomAttributes(): add fastpaths for common cases, add a cache for looking up AttributeUsageAttributes, clean up intendation.
Disable a corlib test which fails on some test runners.