[Driver][Fuchsia] Pass --hash-style=gnu to the linker

The .gnu_hash format is superior, and all versions of the Fuchsia
dynamic linker support it.

Differential Revision: https://reviews.llvm.org/D36254

llvm-svn: 310017

clang/lib/Driver/ToolChains/Fuchsia.cpp

@@ -64,10 +64,12 @@ void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   if (Args.hasArg(options::OPT_s))
     CmdArgs.push_back("-s");
 
-  if (Args.hasArg(options::OPT_r))
+  if (Args.hasArg(options::OPT_r)) {
     CmdArgs.push_back("-r");
-  else
+  } else {
     CmdArgs.push_back("--build-id");
+    CmdArgs.push_back("--hash-style=gnu");
+  }
 
   CmdArgs.push_back("--eh-frame-hdr");
 

clang/test/Driver/fuchsia.c

@@ -9,6 +9,7 @@
 // CHECK: "--sysroot=[[SYSROOT]]"
 // CHECK: "-pie"
 // CHECK: "--build-id"
+// CHECK: "--hash-style=gnu"
 // CHECK: "-dynamic-linker" "ld.so.1"
 // CHECK: Scrt1.o
 // CHECK-NOT: crti.o