Fix the "opt-win" build on Visual Studio 10.0

src/native_client/site_scons/site_tools/target_platform_windows.py

Index: src/native_client/site_scons/site_tools/target_platform_windows.py
diff --git a/src/native_client/site_scons/site_tools/target_platform_windows.py b/src/native_client/site_scons/site_tools/target_platform_windows.py
index 5957593c3610a06eca083e0b1e9055626fb66dd4..75431396863e1f2632465baed66e5f22c5bf68bf 100755
--- a/src/native_client/site_scons/site_tools/target_platform_windows.py
+++ b/src/native_client/site_scons/site_tools/target_platform_windows.py
@@ -404,7 +404,9 @@ def generate(env):
           '/MT',     # link with LIBCMT.LIB (multi-threaded, static linked crt)
           '/GS',     # enable security checks
       ],
-      LINKFLAGS_OPTIMIZED=['/PDBPATH:none'],
+      # Omit the absolute pathname of the .pdb debugging info file
+      # from the executable, and just use a relative pathname.
+      LINKFLAGS_OPTIMIZED=['/PDBALTPATH:%_PDB%'],
 
       # Settings for component_builders
       COMPONENT_LIBRARY_LINK_SUFFIXES=['.lib'],