[Driver] Default Android toolchains to noexecstack.

Android does not support executable stacks.

Reviewers: srhines, pirama

Reviewed By: pirama

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D53343

llvm-svn: 357197
diff --git a/clang/lib/Driver/ToolChains/Linux.h b/clang/lib/Driver/ToolChains/Linux.h
index f70dc5d..4c61994 100644
--- a/clang/lib/Driver/ToolChains/Linux.h
+++ b/clang/lib/Driver/ToolChains/Linux.h
@@ -38,6 +38,7 @@
                            llvm::opt::ArgStringList &CC1Args) const override;
   CXXStdlibType GetDefaultCXXStdlibType() const override;
   bool isPIEDefault() const override;
+  bool isNoExecStackDefault() const override;
   bool IsMathErrnoDefault() const override;
   SanitizerMask getSupportedSanitizers() const override;
   void addProfileRTLibs(const llvm::opt::ArgList &Args,