[lsan] Introduce print_suppressions flag.

Introduce a flag to either always or never print matched suppressions.
Previously, matched suppressions were printed unconditionally if there were
unsuppressed leaks. Also, verbosity=1 no longer has the semantics of "always
print suppressions and summary".

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@197510 91177308-0d34-0410-b5e6-96231b3b80d8
[lsan] Remove the LSan-specific verbosity flag.

It conflicted with the verbosity flag we had in common flags. We don't need an
LSan-specific flag anyway.

Also, shift some logging levels and remove some unnecessary code.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@197512 91177308-0d34-0410-b5e6-96231b3b80d8