raw_svector_ostream: grow and reserve atomically

Including the scratch buffer size in the initial reservation eliminates the
subsequent malloc+move operation and offers a healthier constant growth with
less memory wastage.

When doing this, take care to avoid invalidating the source buffer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212816 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] add_llvm_library: Add "RUNTIME DESTINATION bin" to install(). It affects add_library(SHARED) for Win32.DLL.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212818 91177308-0d34-0410-b5e6-96231b3b80d8
llvm/test/lit.cfg: Let %python available.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212819 91177308-0d34-0410-b5e6-96231b3b80d8
llvm/test/BugPoint/compile-custom.ll: Use explicit %python to invoke a test script, compile-custom.ll.py, for shebang-incapable hosts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212820 91177308-0d34-0410-b5e6-96231b3b80d8