[PATCH] Improvements for asan deactivated mode: disable asan activation for runtime library on Linux, disable malloc checks.

[Evgeniy Stepanov]

Sounds good.
So, we need to
* Flip the default of COMPILER_RT_BUILD_SHARED_ASAN
* Add a new variant for asan unit tests (see -with-calls for example)
* Add new configurations for asan lit tests.

This way we would catch DSO issues before this code is merged to gcc, yay!

Any takers?

http://reviews.llvm.org/D6265