[vm] Allow choosing architecture for runtime sources in generate_idefiles.py.

Change-Id: Ief2207192c6540eed3a335e0db9d91f8cf773538
Reviewed-on: https://dart-review.googlesource.com/c/89145
Auto-Submit: Samir Jindel <sjindel@google.com>
Commit-Queue: Samir Jindel <sjindel@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
diff --git a/tools/generate_idefiles.py b/tools/generate_idefiles.py
index 51b41e6..900c25c 100755
--- a/tools/generate_idefiles.py
+++ b/tools/generate_idefiles.py
@@ -50,7 +50,7 @@
   if gn_result != 0:
     return gn_result
 
-  out_folder = utils.GetBuildRoot(HOST_OS, mode="debug", arch="x64")
+  out_folder = utils.GetBuildRoot(HOST_OS, mode="debug", arch=options.arch)
 
   if not os.path.isdir(out_folder):
     return 1
@@ -136,6 +136,10 @@
                       help="Target directory.",
                       default=utils.DART_DIR)
 
+  parser.add_argument("-a", "--arch",
+                      help="Target architecture for runtime sources.",
+                      default="x64")
+
   options = parser.parse_args(argv[1:])
 
   return GenerateIdeFiles(options)