VS: Map /ENTRY linker option to EntryPointSymbol

Source/cmLocalVisualStudio7Generator.cxx

@@ -466,6 +466,8 @@ cmVS7FlagTable cmLocalVisualStudio7GeneratorLinkFlagTable[] =
   {"GenerateManifest", "MANIFEST", "enable manifest generation", "TRUE", 0},
   {"LinkIncremental", "INCREMENTAL:NO", "link incremental", "1", 0},
   {"LinkIncremental", "INCREMENTAL:YES", "link incremental", "2", 0},
+  {"EntryPointSymbol", "ENTRY:", "sets the starting address", "",
+   cmVS7FlagTable::UserValue},
   {"IgnoreDefaultLibraryNames", "NODEFAULTLIB:", "default libs to ignore", "",
   cmVS7FlagTable::UserValue | cmVS7FlagTable::SemicolonAppendable},
   {"IgnoreAllDefaultLibraries", "NODEFAULTLIB", "ignore all default libs",