[asan] Default to memory-mapped coverage on Android.

The alternative (writing coverage at process exit) is nearly useless there.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@210024 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan Win] Fix memset interception in DLLs

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@210027 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer/interception Win] Break into the debugger on unknown instructions

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@210028 91177308-0d34-0410-b5e6-96231b3b80d8