[asan] Since r280945 fixed the OS X abort() problem, merge...

[asan] Since r280945 fixed the OS X abort() problem, merge scariness_score_test.cc and make it a general test.

Summary: Merges back both scariness_score_test.cc files, since the Linux-specific version shouldn't be needed any more.

Reviewers: kcc, eugenis, vitalybuka

Subscribers: llvm-commits, kubabrecka

Differential Revision: https://reviews.llvm.org/D24347

llvm-svn: 281048