vs2010: give each target an own temp dir

The 'Rebuild' target fails in mysterious ways if multiple targets use
the same directories because of output files being deleted between two
build steps (e.g. test case 78 fails on Rebuild, whereas Clean + Build
work just fine).

mesonbuild/backend/vs2010backend.py

@@ -272,7 +272,7 @@ class Vs2010Backend(backends.Backend):
         outdir = ET.SubElement(direlem, 'OutDir')
         outdir.text = '.\\'
         intdir = ET.SubElement(direlem, 'IntDir')
-        intdir.text = 'test-temp\\'
+        intdir.text = target.get_id() + '\\'
         tname = ET.SubElement(direlem, 'TargetName')
         tname.text = target.name
         return root
@@ -395,7 +395,7 @@ class Vs2010Backend(backends.Backend):
         outdir = ET.SubElement(direlem, 'OutDir')
         outdir.text = '.\\'
         intdir = ET.SubElement(direlem, 'IntDir')
-        intdir.text = os.path.join(self.get_target_dir(target), target.get_basename() + '.dir') + '\\'
+        intdir.text = target.get_id() + '\\'
         tname = ET.SubElement(direlem, 'TargetName')
         tname.text = target_name
         inclinc = ET.SubElement(direlem, 'LinkIncremental')
@@ -604,7 +604,7 @@ class Vs2010Backend(backends.Backend):
         outdir = ET.SubElement(direlem, 'OutDir')
         outdir.text = '.\\'
         intdir = ET.SubElement(direlem, 'IntDir')
-        intdir.text = 'test-temp\\'
+        intdir.text = 'regen-temp\\'
         tname = ET.SubElement(direlem, 'TargetName')
         tname.text = project_name