CMake: replace `rm' with portable invocations of cmake.

Based on a bug report by Yonggang Luo.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61875 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/modules/AddPartiallyLinkedObject.cmake b/cmake/modules/AddPartiallyLinkedObject.cmake
index e13574b..fd5069d 100755
--- a/cmake/modules/AddPartiallyLinkedObject.cmake
+++ b/cmake/modules/AddPartiallyLinkedObject.cmake
@@ -30,7 +30,7 @@
       WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/temp_lib
       COMMAND ar x ${CMAKE_STATIC_LIBRARY_PREFIX}${lib}${CMAKE_STATIC_LIBRARY_SUFFIX}
       COMMAND ${CMAKE_LINKER} "${LLVM_PLO_FLAGS}" -r "*${CMAKE_CXX_OUTPUT_EXTENSION}" -o ${pll}
-      COMMAND rm -f *${CMAKE_CXX_OUTPUT_EXTENSION}
+      COMMAND ${CMAKE_COMMAND} -E remove -f *${CMAKE_CXX_OUTPUT_EXTENSION}
       )
     target_name_of_partially_linked_object(${lib} tnplo)
     add_custom_target(${tnplo} ALL DEPENDS ${pll})