[scudo][standalone] Allow Primary allocations to fail up multiple times.

Summary:
When enabling some malloc debug features on Android, multiple 32 bit
regions become exhausted, and the allocations fail. Allow allocations
to keep trying each bigger class in the Primary until it finds a fit.
In addition, some Android tests running on 32 bit fail sometimes due
to a running out of space in two regions, and then fail the allocation.

Reviewers: cryptoad

Reviewed By: cryptoad

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D82070