[vm] Build elf_loader and crashpad with correct TARGET_OS

Previously they were built with TARGET_OS_FUCHSIA regardless of target OS.

TEST=ci

Change-Id: I53e95bb61c3926334e861ed56ceb3ea018e7bf1a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/347202
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
diff --git a/runtime/bin/BUILD.gn b/runtime/bin/BUILD.gn
index 1b95a53..52cd4bb 100644
--- a/runtime/bin/BUILD.gn
+++ b/runtime/bin/BUILD.gn
@@ -120,7 +120,7 @@
     "..:dart_arch_config",
     "..:dart_config",
     "..:dart_product_config",
-    "..:dart_os_fuchsia_config",
+    "..:dart_os_config",
   ]
   include_dirs = [ ".." ]
   sources = [ "crashpad.cc" ]
@@ -144,7 +144,7 @@
     configs += [
       "..:dart_arch_config",
       "..:dart_config",
-      "..:dart_os_fuchsia_config",
+      "..:dart_os_config",
       "..:dart_product_config",
       "..:dart_shared_lib",
     ]