versioner: compile with `clang -include foo.h -`.

At least one warning only triggers in files that are included, instead
of being passed directly. Switch to compiling with -include, and fix
the resulting warnings.

Bug: https://github.com/android-ndk/ndk/issues/474
Test: mma -j && versioner
Test: python tools/versioner/run_tests.py
Change-Id: I784698c18540c9cc30f372f279a1cec1d75721ea
diff --git a/tools/versioner/src/Driver.cpp b/tools/versioner/src/Driver.cpp
index 1b631b6..a094818 100644
--- a/tools/versioner/src/Driver.cpp
+++ b/tools/versioner/src/Driver.cpp
@@ -100,11 +100,12 @@
   std::vector<std::string> cmd = { "versioner" };
   cmd.push_back("-std=c11");
   cmd.push_back("-x");
-  cmd.push_back("c-header");
+  cmd.push_back("c");
   cmd.push_back("-fsyntax-only");
 
   cmd.push_back("-Wall");
   cmd.push_back("-Wextra");
+  cmd.push_back("-Weverything");
   cmd.push_back("-Werror");
   cmd.push_back("-Wundef");
   cmd.push_back("-Wno-unused-macros");
@@ -134,7 +135,9 @@
     cmd.push_back(dir);
   }
 
+  cmd.push_back("-include");
   cmd.push_back(filename_placeholder);
+  cmd.push_back("-");
 
   auto diags = constructDiags();
   driver::Driver driver("versioner", llvm::sys::getDefaultTargetTriple(), *diags, vfs);