Add instructions for building LLDB with CMake
- suported generators: Ninja and Unix Makefiles
- added instructions to run tests when building with autoconf



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@176522 91177308-0d34-0410-b5e6-96231b3b80d8
Typos: be more precise on the build page when mentioning the non-cmake build system



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@176524 91177308-0d34-0410-b5e6-96231b3b80d8
Be more precise in GCC/autoconf build instructions about compiler versions



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@176528 91177308-0d34-0410-b5e6-96231b3b80d8