[PATCH] [libcxxabi] Add a cmake build system.

[Alexey Samsonov]

I don't really understand why (most of) compiler flags are set up in the root CMakeLists.txt, while the link flags are set up in src/CMakeLists.txt, but probably that's not a big deal.

Thanks for working on this!

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Comment at: src/CMakeLists.txt:39
@@ +38,3 @@
+# Setup flags.
+append_if(compile_flags LIBCXXABI_HAS_FPIC_FLAG -fPIC)
+append_if(link_flags LIBCXXABI_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
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Why not use "set" here?

================
Comment at: src/CMakeLists.txt:57
@@ +56,3 @@
+
+string(REPLACE ";" " " link_flags "${link_flags}")
+
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Do you need to do the same for compile_flags?

http://reviews.llvm.org/D4359