[Bash-autocompletion] Pass all flags in shell command-line to Clang

Previously, we passed "#" to --autocomplete to indicate to enable cc1
flags. For example, when -cc1 or -Xclang was passed to bash, bash
executed `clang --autocomplete=#-<flag they want to complete>`.

However, this was not a good implementation because it depends -Xclang
and -cc1 parsing to shell. So I changed this to pass all flags shell
has, so that Clang can handle them internally.

I had to change many testcases because API spec changed quite a lot.

Reviewers: teemperor, v.g.vassilev

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D39342

llvm-svn: 326684
diff --git a/llvm/lib/Option/OptTable.cpp b/llvm/lib/Option/OptTable.cpp
index dcd1cc4..5956764 100644
--- a/llvm/lib/Option/OptTable.cpp
+++ b/llvm/lib/Option/OptTable.cpp
@@ -219,7 +219,7 @@
 
     std::vector<std::string> Result;
     for (StringRef Val : Candidates)
-      if (Val.startswith(Arg))
+      if (Val.startswith(Arg) && Arg.compare(Val))
         Result.push_back(Val);
     return Result;
   }
@@ -240,7 +240,7 @@
       std::string S = std::string(In.Prefixes[I]) + std::string(In.Name) + "\t";
       if (In.HelpText)
         S += In.HelpText;
-      if (StringRef(S).startswith(Cur))
+      if (StringRef(S).startswith(Cur) && S.compare(std::string(Cur) + "\t"))
         Ret.push_back(S);
     }
   }