include obj name in shared intermediate

avoids duplicate ninja rules for v8 used in host and target

tools/gyp/pylib/gyp/generator/ninja.py

@@ -46,7 +46,7 @@
     # the start of a string, while $| is used for variables that can appear
     # anywhere in a string.
     "INTERMEDIATE_DIR": "$!INTERMEDIATE_DIR",
-    "SHARED_INTERMEDIATE_DIR": "$!PRODUCT_DIR/gen",
+    "SHARED_INTERMEDIATE_DIR": "$!PRODUCT_DIR/$|OBJ/gen",
     "PRODUCT_DIR": "$!PRODUCT_DIR",
     "CONFIGURATION_NAME": "$|CONFIGURATION_NAME",
     # Special variables that may be used by gyp 'rule' targets.
@@ -289,6 +289,12 @@ def ExpandSpecial(self, path, product_dir=None):
         CONFIGURATION_NAME = "$|CONFIGURATION_NAME"
         path = path.replace(CONFIGURATION_NAME, self.config_name)
 
+        obj = "obj"
+        if self.toolset != "target":
+            obj += "." + self.toolset
+
+        path = path.replace("$|OBJ", obj)
+
         return path
 
     def ExpandRuleVariables(self, path, root, dirname, source, ext, name):