tests: Disable page allocator if address sanitizer is active
tests: Disable page allocator if address sanitizer is active

Address sanitizer can detect underflows so we don't really need the custom
allocator.

Additionally, custom allocator can return memory that is not pointer-aligned;
this causes undefined behavior sanitizer to complain.

zeux/pugixml,zeux/pugixml,zeux/pugixml,zeux/pugixml