[infra] Use x64 reclient on Windows ARM64.

Switch build to use Clang. This somewhat degrades FFI testing, but reduces build time by roughly half or one hour.

Cq-Include-Trybots: luci.dart.try:pkg-win-release-arm64-try,vm-aot-win-debug-arm64-try,vm-aot-win-release-arm64-try,vm-win-debug-arm64-try,vm-win-release-arm64-try
Change-Id: Ie267942e99934312b228cfadcd6d5b8477f855c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429421
Commit-Queue: Ryan Macnak <[email protected]>
Reviewed-by: Alexander Aprelev <[email protected]>

Author: rmacnak-google

DEPS

@@ -470,6 +470,19 @@ deps = {
     'dep_type': 'cipd',
   },
 
+  # windows-arm64 package is not available, use the windows-x64 package and
+  # rely on transparent emulation.
+  Var("dart_root") + '/buildtools/reclient-win': {
+    'packages': [
+      {
+        'package': 'infra/rbe/client/windows-amd64',
+        'version': Var('reclient_version'),
+      }
+    ],
+    'condition': 'host_os == "win"',
+    'dep_type': 'cipd',
+  },
+
   Var("dart_root") + "/third_party/webdriver/chrome": {
     "packages": [
       {
@@ -491,6 +504,9 @@ deps = {
       "condition": "host_os != 'win'",
       "dep_type": "cipd",
   },
+
+  # windows-arm64 package is not available, use the windows-x64 package and
+  # rely on transparent emulation.
   Var("dart_root") + "/buildtools/win": {
       "packages": [
           {

build/toolchain/rbe.gni

@@ -26,7 +26,12 @@ declare_args() {
 
   rbe_exec_root = rebase_path("//", root_build_dir)
 
-  rbe_dir = rebase_path(_dart_root + "/buildtools/reclient", root_build_dir)
+  if (host_os == "win") {
+    rbe_dir =
+        rebase_path(_dart_root + "/buildtools/reclient-win", root_build_dir)
+  } else {
+    rbe_dir = rebase_path(_dart_root + "/buildtools/reclient", root_build_dir)
+  }
 }
 
 declare_args() {

tools/bots/test_matrix.json

@@ -1770,32 +1770,14 @@
         "vm-win-release-arm64"
       ],
       "meta": {
-        "description": "This configuration is for the ARM64 JIT builders, no shards.",
-        "__comment__": "--no-clang because Clang is inconsisent about varargs: dartbug.com/52644"
+        "description": "This configuration is for the ARM64 JIT builders, no shards."
       },
       "steps": [
         {
-          "name": "build dart - step 1 - gen-snapshot - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "--no-clang",
-            "gen_snapshot"
-          ]
-        },
-        {
-          "name": "build dart - step 2 - runtime/bin:dart - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "--no-clang",
-            "runtime/bin:dart",
-            "runtime/bin:run_vm_tests"
-          ]
-        },
-        {
-          "name": "build dart - step 3 - runtime - divided to avoid timeout",
+          "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
-            "--no-clang",
+            "--rbe",
             "runtime"
           ]
         },
@@ -1821,32 +1803,16 @@
         "vm-aot-win-release-arm64"
       ],
       "meta": {
-        "description": "This configuration is for the ARM64 AOT builders, no shards.",
-        "__comment__": "--no-clang because Clang is inconsisent about varargs: dartbug.com/52644"
+        "description": "This configuration is for the ARM64 AOT builders, no shards."
       },
       "steps": [
         {
-          "name": "build dart - step 1 - gen-snapshot - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "--no-clang",
-            "gen_snapshot"
-          ]
-        },
-        {
-          "name": "build dart - step 2 - runtime - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "--no-clang",
-            "dartaotruntime"
-          ]
-        },
-        {
-          "name": "build dart - step 3 - runtime/bin:dart - divided to avoid timeout",
+          "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
-            "--no-clang",
-            "runtime"
+            "--rbe",
+            "runtime",
+            "runtime_precompiled"
           ]
         },
         {
@@ -3189,32 +3155,12 @@
           ]
         },
         {
-          "name": "build dart - step 1 - gen-snapshot - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "gen_snapshot"
-          ]
-        },
-        {
-          "name": "build dart - step 2 - runtime/bin:dart - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "runtime/bin:dart",
-            "runtime/bin:run_vm_tests"
-          ]
-        },
-        {
-          "name": "build dart - step 3 - runtime - divided to avoid timeout",
-          "script": "tools/build.py",
-          "arguments": [
-            "runtime"
-          ]
-        },
-        {
-          "name": "build dart - step 4 - sdk, ddc_stable_test - divided to avoid timeout",
+          "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
+            "--rbe",
             "create_sdk",
+            "dartanalyzer",
             "ddc_stable_test"
           ]
         },

tools/build.py

@@ -134,7 +134,10 @@ def UseRBE(out_dir):
 def StartRBE(out_dir, env):
     global rbe_started, bootstrap_path
     if not rbe_started:
-        rbe_dir = 'buildtools/reclient'
+        if utils.IsWindows():
+          rbe_dir = 'buildtools/reclient-win'
+        else:
+          rbe_dir = 'buildtools/reclient'
         with open(os.path.join(out_dir, 'args.gn'), 'r') as fp:
             for line in fp:
                 if 'rbe_dir' in line: