Do not use -o with Vala. Closes #120.

compilers.py

@@ -801,14 +801,13 @@ class ValaCompiler():
 
     def sanity_check(self, work_dir):
         src = 'valatest.vala'
-        obj = 'valatest.c'
         source_name = os.path.join(work_dir, src)
         ofile = open(source_name, 'w')
         ofile.write('''class SanityCheck : Object {
 }
 ''')
         ofile.close()
-        pc = subprocess.Popen(self.exelist + ['-C', '-o', obj, src], cwd=work_dir)
+        pc = subprocess.Popen(self.exelist + ['-C', '-c', src], cwd=work_dir)
         pc.wait()
         if pc.returncode != 0:
             raise EnvironmentException('Vala compiler %s can not compile programs.' % self.name_string())

ninjabackend.py

@@ -683,7 +683,7 @@ class NinjaBackend(backends.Backend):
                 continue
             args = ['-d', self.get_target_private_dir(target)]
             sc = os.path.basename(s.fname)[:-4] + 'c'
-            args += ['-C', '-o', sc]
+            args += ['-C']
             vapi_order_deps = []
             for (sourcefile, vapi_info) in fast_vapis.items():
                 if sourcefile == s: