[ARM] Add a driver option for +no-neg-immediates

Reviewers: olista01, rengolin, javed.absar, samparker

Reviewed By: samparker

Subscribers: samparker, llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D31197

llvm-svn: 298850
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index 7dc2f57..554d051 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -193,4 +193,7 @@
 
   if (Args.hasArg(options::OPT_ffixed_x18))
     Features.push_back("+reserve-x18");
+
+  if (Args.hasArg(options::OPT_mno_neg_immediates))
+    Features.push_back("+no-neg-immediates");
 }