CMake: Add LLVM_UTILS_INSTALL_DIR option

Summary:
This is like the LLVM_TOOLS_INSTALL_DIR option, but for the utils
that are installed when the LLVM_INSTALL_UTILS.  This option
defaults to 'bin' to remain consistent with the current behavior, but
distros may want to install these to libexec/llvm.

Reviewers: beanz

Reviewed By: beanz

Subscribers: llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D30655

llvm-svn: 307150
diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 2b54bdb..f4d5f46 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -865,7 +865,7 @@
   set_target_properties(${name} PROPERTIES FOLDER "Utils")
   if( LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS )
     install (TARGETS ${name}
-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${LLVM_UTILS_INSTALL_DIR}
       COMPONENT ${name})
     if (NOT CMAKE_CONFIGURATION_TYPES)
       add_custom_target(install-${name}