Merge changes I76ce981e,Ifd00d52e,Ibc6fa38b,Ic3aa6a74

* changes:
  scudo: Support memory tagging in the secondary allocator.
  [scudo/standalone] Use .arch_extension memtag, not mte
  [GWP-ASan] Add aligned allocations.
  [scudo/standalone] Use zx_system_get_page_size() on Fuchsia
diff --git a/Android.bp b/Android.bp
index 68ec79a..ac97ad5 100644
--- a/Android.bp
+++ b/Android.bp
@@ -161,7 +161,9 @@
 
 cc_test {
     name: "scudo_unit_tests",
-    host_supported: true,
+    // Temporarily disabled on host due to a 15-20s per-test timeout,
+    // which is currently exceeded by ScudoCombinedTest.BasicCombined.
+    host_supported: false,
     srcs: [
         "standalone/tests/atomic_test.cpp",
         "standalone/tests/bytemap_test.cpp",
diff --git a/copybara/copy.bara.sky b/copybara/copy.bara.sky
index 6c2d036..54ca37c 100644
--- a/copybara/copy.bara.sky
+++ b/copybara/copy.bara.sky
@@ -2,7 +2,7 @@
     name = "default",
     origin = git.origin(
         url = "https://github.com/llvm/llvm-project.git",
-        ref = "master",
+        ref = "main",
     ),
     origin_files = glob(
         [