Fix Windows dump_syms x64 linking

The dia_sdk GYP target points at the x86 diaguids.lib, it needs to
point at the x64 one for x64 builds.
R=mark at https://breakpad.appspot.com/9784002/

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1431 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/windows/common_windows.gyp

@@ -37,16 +37,34 @@
       'all_dependent_settings': {
         'include_dirs': [
           '<(DEPTH)',
-          '$(VSInstallDir)\DIA SDK\include',
+          '$(VSInstallDir)/DIA SDK/include',
         ],
         'msvs_settings': {
           'VCLinkerTool': {
             'AdditionalDependencies': [
-              '$(VSInstallDir)\DIA SDK\lib\diaguids.lib',
+              'diaguids.lib',
               'imagehlp.lib',
             ],
           },
         },
+        'configurations': {
+          'x86_Base': {
+            'msvs_settings': {
+              'VCLinkerTool': {
+                'AdditionalLibraryDirectories':
+                  ['$(VSInstallDir)/DIA SDK/lib'],
+              },
+            },
+          },
+          'x64_Base': {
+            'msvs_settings': {
+              'VCLinkerTool': {
+                'AdditionalLibraryDirectories':
+                  ['$(VSInstallDir)/DIA SDK/lib/amd64'],
+              },
+            },
+          },
+        },
       },
     },
     {