ARROW-2675: Fix build error with clang-10 (Apple Clang / LLVM)

[songqing]

As mac os X has been updated to the version 10.13.5, XCode has been updated to XCode 9.4 and Command Line Tools have been updated to the version 10.0, the clang version has also been updated to clang-10 (Apple Clang / LLVM) correspondingly. However, Arrow can only be built under clang-9, as shown in the file

arrow/cpp/cmake_modules/CompilerInfo.cmake

Line 77 in b1d1633

elseif("${COMPILER_VERSION_FULL}" MATCHES ".*clang-9")

So, it's time to update Arrow to support clang-10.

[codecov-io]

Codecov Report

Merging #2106 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2106   +/-   ##
=======================================
  Coverage   86.37%   86.37%           
=======================================
  Files         230      230           
  Lines       40458    40458           
=======================================
  Hits        34946    34946           
  Misses       5512     5512

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[xhochy]

+1, looks good. Can you create an issue over at to track this show it shows up in the changelog? https://issues.apache.org/jira/projects/ARROW

[songqing]

@xhochy already created the issue. https://issues.apache.org/jira/browse/ARROW-2675

[xhochy]

Thanks!

[wesm]

You mean XCode 10 instead of clang-10, right? Can you update the PR title and code comments to indicate this?

[songqing]

@wesm I really mean clang-10. Sorry not to mention the version of XCode, it's XCode 9.4 and I'll update it. The build error with clang-10 is shown as below.

[wesm]

OK, the LLVM project uses different version numbers to talk about Clang. The current stable version of LLVM is 6, and so Linux distributions use clang-6.0 as the name of the Clang package. I guess we need to distinguish by saying "Apple Clang / LLVM" to avoid confusion

[songqing]

@wesm OK, I have changed it.

[songqing]

@xhochy This PR has fixed the build bug and tested successfully, I think you can merge it now.

[xhochy]

+1, LGTM

Thanks for fixing it and taking care for the ticket naming.