[cmake] Provide an option to not install the support headers so that the cmake build can match the make build if requested.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189739 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e56b061..9723d26 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,6 +38,7 @@
 option(LIBCXX_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
 option(LIBCXX_ENABLE_CXX0X "Enable -std=c++0x and use of c++0x language features if the compiler supports it." ON)
 option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
+option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
 
 set(CXXABIS none libcxxabi libcxxrt libsupc++)
 if (NOT DEFINED LIBCXX_CXX_ABI)
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 45effcc..9f28f68 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -100,9 +100,15 @@
   ARCHIVE DESTINATION lib
   )
 
+
+if (NOT LIBCXX_INSTALL_SUPPORT_HEADERS)
+  set(LIBCXX_SUPPORT_HEADER_PATTERN PATTERN "support" EXCLUDE)
+endif()
+
 install(DIRECTORY ../include/
   DESTINATION include/c++/v1
   FILES_MATCHING
   PATTERN "*"
   PATTERN ".svn" EXCLUDE
+  ${LIBCXX_SUPPORT_HEADER_PATTERN}
   )