ARROW-1909: [C++] Enables building with benchmarks on windows

[seibs]

These changes were necessary to compile on Windows with "-DARROW_BUILD_BENCHMARKS=ON". I added Shwlapi based on google/benchmark#202.

[wesm]

Sweet, thank you. I will take this for a spin when I get a chance and merge if no issues

[seibs]

@xhochy - responding to your comments from #1422 here. I reverted the white space change as requested, but the int64_t to int change was required to build on Windows, so I left it as is. When set to int64_t, the build failed complaining about a cast from int64_t to int.

[wesm]

I added LL to make that an int64 literal. Merging once the build runs

[seibs]

Awesome, thanks @wesm - once this is merged I'll rebase my other open pull request.

[wesm]

Turns out the the Args option in google benchmark doesn't accept int64_t. Sorry about the confusion, I've reverted