[Hexagon] Use GetLinkerPath instead of hard-coded string.

Add GetLinkerPath and set the default to "hexagon-link".
Use GetLinkerPath instead of the hard-coded string.

This change will allow -fuse-ld to function correctly.

Differential revision: https://reviews.llvm.org/D53038

llvm-svn: 344147
diff --git a/clang/lib/Driver/ToolChains/Hexagon.cpp b/clang/lib/Driver/ToolChains/Hexagon.cpp
index b4f299a..8778a1a 100644
--- a/clang/lib/Driver/ToolChains/Hexagon.cpp
+++ b/clang/lib/Driver/ToolChains/Hexagon.cpp
@@ -369,9 +369,8 @@
   constructHexagonLinkArgs(C, JA, HTC, Output, Inputs, Args, CmdArgs,
                            LinkingOutput);
 
-  std::string Linker = HTC.GetProgramPath("hexagon-link");
-  C.addCommand(llvm::make_unique<Command>(JA, *this, Args.MakeArgString(Linker),
-                                          CmdArgs, Inputs));
+  const char *Exec = Args.MakeArgString(HTC.GetLinkerPath());
+  C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
 }
 // Hexagon tools end.