Pull loader.[cc|h] file out of libdart_builtin rule and instead include it in each of the targets (…

runtime/bin/BUILD.gn

Index: runtime/bin/BUILD.gn
diff --git a/runtime/bin/BUILD.gn b/runtime/bin/BUILD.gn
index e053aa5cab0e0037bb1c1dd9b8ed8505e2e8a5af..19f0fd8c385898cb22fcac7eb745f01a7998af98 100644
--- a/runtime/bin/BUILD.gn
+++ b/runtime/bin/BUILD.gn
@@ -287,6 +287,8 @@ executable("gen_snapshot") {
     "address_sanitizer.cc",
     "builtin.cc",
     "builtin.h",
+    "loader.cc",
+    "loader.h",
 
     # Very limited native resolver provided.
     "builtin_common.cc",
@@ -618,7 +620,11 @@ dart_executable("dart") {
     ":dart_snapshot_cc",
     "../observatory:standalone_observatory_archive",
   ]
-  extra_sources = [ "builtin_nolib.cc" ]
+  extra_sources = [
+    "builtin_nolib.cc",
+    "loader.cc",
+    "loader.h",
+  ]
 }
 
 dart_executable("dart_precompiled_runtime") {
@@ -630,6 +636,8 @@ dart_executable("dart_precompiled_runtime") {
   extra_sources = [
     "builtin_nolib.cc",
     "snapshot_empty.cc",
+    "loader.cc",
+    "loader.h",
   ]
 }
 
@@ -660,6 +668,8 @@ dart_executable("dart_bootstrap") {
   extra_sources = [
     "builtin.cc",
     "builtin.h",
+    "loader.cc",
+    "loader.h",
     "observatory_assets_empty.cc",
     "snapshot_empty.cc",