[build] Fix false detection of compressed pointers as cross builds.

Broken by 3c01efcbb07cb1af8da0e13d8edca79457188062.

TEST=fuzzer
Change-Id: Ifefdd1864de969b82f10471f4184c1169ec9aaba
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244741
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
diff --git a/tools/utils.py b/tools/utils.py
index d3401f1..9141d93 100644
--- a/tools/utils.py
+++ b/tools/utils.py
@@ -265,6 +265,9 @@
         return True
     if arch.startswith('sim'):
         return False
+    if arch.endswith('c'):
+        # Strip 'compressed' suffix.
+        arch = arch[:-1]
     if arch in HostArchitectures():
         return False
     return True