Define --output= as an alias to -o.

llvm-svn: 249789
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 2ae38c9..b4395e8 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -188,7 +188,7 @@
   Config->Entry = getString(Args, OPT_entry);
   Config->Fini = getString(Args, OPT_fini, "_fini");
   Config->Init = getString(Args, OPT_init, "_init");
-  Config->OutputFile = getString(Args, OPT_output);
+  Config->OutputFile = getString(Args, OPT_o);
   Config->SoName = getString(Args, OPT_soname);
   Config->Sysroot = getString(Args, OPT_sysroot);
 
diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index dfa6dd6..4951b4d 100644
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -61,7 +61,7 @@
 def no_undefined : Flag<["--"], "no-undefined">,
   HelpText<"Report unresolved symbols even if the linker is creating a shared library">;
 
-def output : Separate<["-"], "o">, MetaVarName<"<path>">,
+def o : Separate<["-"], "o">, MetaVarName<"<path>">,
   HelpText<"Path to file to write output">;
 
 def rpath : Separate<["-"], "rpath">,
@@ -98,6 +98,7 @@
 def alias_fini_fini : Joined<["-"], "fini=">, Alias<fini>;
 def alias_init_init : Joined<["-"], "init=">, Alias<init>;
 def alias_l__library : Joined<["--"], "library=">, Alias<l>;
+def alias_o_output : Joined<["--"], "output=">, Alias<o>;
 def alias_rpath_rpath : Joined<["-"], "rpath=">, Alias<rpath>;
 def alias_soname_h : Separate<["-"], "h">, Alias<soname>;
 def alias_soname_soname : Separate<["-"], "soname">, Alias<soname>;