[gn build] Add lldb to default target on Windows

It seems to build fine (even though some tests fail), so might
as well let the bots build it. If it turns out to break a lot,
we can always turn it back off.

Differential Revision: https://reviews.llvm.org/D112620

llvm/utils/gn/secondary/BUILD.gn

@@ -12,6 +12,7 @@ group("default") {
     "//compiler-rt/include",
     "//compiler-rt/lib/scudo",
     "//lld/test",
+    "//lldb/test",
     "//llvm/test",
   ]
   if (current_os == "linux") {
@@ -20,9 +21,6 @@ group("default") {
       "//libcxxabi",
     ]
   }
-  if (current_os == "linux" || current_os == "mac") {
-    deps += [ "//lldb/test" ]
-  }
   if (current_os == "linux" || current_os == "android") {
     deps += [ "//compiler-rt/test/hwasan" ]
   }