Add LLVMCoroutines lib for llvm>=4.0 builds

Building bcc against a tip of tree llvm introduces a new link failure,
which is fixed by linking against libLLVMCoroutines (which only exists
in 4.0).
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

src/cc/CMakeLists.txt

@@ -49,6 +49,10 @@ list(FIND LLVM_AVAILABLE_LIBS "LLVMCoverage" _llvm_coverage)
 if (${_llvm_coverage} GREATER -1)
   list(APPEND llvm_raw_libs coverage)
 endif()
+list(FIND LLVM_AVAILABLE_LIBS "LLVMCoroutines" _llvm_coroutines)
+if (${_llvm_coroutines} GREATER -1)
+  list(APPEND llvm_raw_libs coroutines)
+endif()
 llvm_map_components_to_libnames(llvm_libs ${llvm_raw_libs})
 llvm_expand_dependencies(expanded_libs ${llvm_libs})