New clang option -mpie-copy-relocations to use copy relocations for PIE builds.

Differential Revision: https://reviews.llvm.org/D19996

llvm-svn: 284638
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 39588e8..03d400b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -586,6 +586,8 @@
   Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
   Opts.IncrementalLinkerCompatible =
       Args.hasArg(OPT_mincremental_linker_compatible);
+  Opts.PIECopyRelocations =
+      Args.hasArg(OPT_mpie_copy_relocations);
   Opts.OmitLeafFramePointer = Args.hasArg(OPT_momit_leaf_frame_pointer);
   Opts.SaveTempLabels = Args.hasArg(OPT_msave_temp_labels);
   Opts.NoDwarfDirectoryAsm = Args.hasArg(OPT_fno_dwarf_directory_asm);