[snapshot] Move builtins generation into mksnapshot

test/unittests/BUILD.gn

Index: test/unittests/BUILD.gn
diff --git a/test/unittests/BUILD.gn b/test/unittests/BUILD.gn
index 2d5726b0b35f61ed384a08f6ae1d619ab8dab028..9c50280ec5692b0523b7627913a688c8ce0236b0 100644
--- a/test/unittests/BUILD.gn
+++ b/test/unittests/BUILD.gn
@@ -185,7 +185,7 @@ v8_executable("unittests") {
   #}],
 
   deps = [
-    "../..:v8",
+    "../..:v8_builtins_generators",
     "../..:v8_libbase",
     "../..:v8_libplatform",
     "//build/config/sanitizers:deps",
@@ -198,6 +198,17 @@ v8_executable("unittests") {
     deps += [ "//third_party/icu" ]
   }
 
+  defines = []
+
+  if (is_component_build) {
+    # unittests can't be built against a shared library, so we
+    # need to depend on the underlying static target in that case.
+    deps += [ "../..:v8_maybe_snapshot" ]
+    defines += [ "BUILDING_V8_SHARED" ]
+  } else {
+    deps += [ "../..:v8" ]
+  }
+
   if (is_win) {
     # This warning is benignly triggered by the U16 and U32 macros in
     # bytecode-utils.h.