Revert of Make it possible to compile d8 for the host toolset as well (https://codereview.chromium.org/139493002/)

Reason for revert:
still doesn't work on arm

Original issue's description:
> Make it possible to compile d8 for the host toolset as well
>
> 2nd attempt. Use a different output path for the host d8.
>
> BUG=v8:1775
> R=machenbach@chromium.org
> LOG=n
>
> Committed: https://code.google.com/p/v8/source/detail?r=18621

R=machenbach@chromium.org
TBR=machenbach@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=v8:1775

Review URL: https://codereview.chromium.org/139523003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18623 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8.gyp

@@ -48,17 +48,7 @@
       'sources': [
         'd8.cc',
       ],
-      'target_conditions': [
-        [ '_toolset == "host"', {
-          'product_dir': '<(PRODUCT_DIR)/host',
-        }],
-      ],
       'conditions': [
-        [ 'want_separate_host_toolset==1', {
-          'toolsets': ['host', 'target'],
-        }, {
-          'toolsets': ['target'],
-        }],
         [ 'console=="readline"', {
           'libraries': [ '-lreadline', ],
           'sources': [ 'd8-readline.cc' ],