Bump system Xcode on ToTMac, ToTMac (dbg), ToTMacAsan, ToTMacCoverage from 11 to 12.

...and re-enable building arm64 isolator runtimes on regular tot bots.

The theory is that this didn't work because system Xcode on these four bots was
too old, so make it less old and try again.

Bug: 1145151
Change-Id: Ic996a91bba98e53934af8db90fdc912b8dae147b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2519206
Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Auto-Submit: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824214}

infra/config/generated/cr-buildbucket.cfg

@@ -8245,7 +8245,7 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"11a1027\"}"
+      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"12a7209\"}"
       execution_timeout_secs: 43200
       build_numbers: YES
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
@@ -8282,7 +8282,7 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"11a1027\"}"
+      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"12a7209\"}"
       execution_timeout_secs: 43200
       build_numbers: YES
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
@@ -8319,7 +8319,7 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"11a1027\"}"
+      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium\",\"xcode_build_version\":\"12a7209\"}"
       execution_timeout_secs: 43200
       build_numbers: YES
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
@@ -8356,7 +8356,7 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium_clang_coverage_tot\",\"xcode_build_version\":\"11a1027\"}"
+      properties: "{\"$build/goma\":{\"use_luci_auth\":true},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"$recipe_engine/isolated\":{\"server\":\"https://isolateserver.appspot.com\"},\"builder_group\":\"chromium.clang\",\"perf_dashboard_machine_group\":\"ChromiumClang\",\"recipe\":\"chromium_clang_coverage_tot\",\"xcode_build_version\":\"12a7209\"}"
       execution_timeout_secs: 43200
       build_numbers: YES
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"

infra/config/lib/ci.star

@@ -523,7 +523,10 @@ def clang_mac_builder(*, name, cores = 24, **kwargs):
         os = builders.os.MAC_10_15,
         ssd = True,
         properties = {
-            "xcode_build_version": "11a1027",
+            # The Chromium build doesn't need system Xcode, but the ToT clang
+            # bots also build clang and llvm and that build does need system
+            # Xcode.
+            "xcode_build_version": "12a7209",
         },
         **kwargs
     )

tools/clang/scripts/build.py

@@ -782,11 +782,6 @@ def main():
     '-DCOMPILER_RT_BUILD_XRAY=OFF',
   ]
   if sys.platform == 'darwin':
-    # TODO(crbug.com/1145151): Figure out why arm64 causes build errors on
-    # the tot bots, fix that, and always build arm64 in iossim_archs.
-    iossim_archs = 'i386;x86_64'
-    if args.bootstrap:
-      iossim_archs += ';arm64'
     compiler_rt_args.extend([
         '-DCOMPILER_RT_BUILD_BUILTINS=ON',
         '-DCOMPILER_RT_ENABLE_IOS=ON',
@@ -795,7 +790,7 @@ def main():
         # armv7 is A5 and earlier, armv7s is A6+ (2012 and later, before 64-bit
         # iPhones). armv7k is Apple Watch, which we don't need.
         '-DDARWIN_ios_ARCHS=armv7;armv7s;arm64',
-        '-DDARWIN_iossim_ARCHS=' + iossim_archs,
+        '-DDARWIN_iossim_ARCHS=i386;x86_64;arm64',
     ])
     if args.bootstrap:
       # mac/arm64 needs MacOSX11.0.sdk. System Xcode (+ SDK) on the chrome bots