[infra] Add MSVC windows to test matrix

Includes precompiled build targets to ensure we try to build most of the
C++ code.

Does not include any tests. We assume that if the build succeeds the
executables will behave the same. If this turns out to not be the case,
we could add a tests later.

Bug: https://github.com/dart-lang/sdk/issues/48544

Change-Id: I5f6b74676d9bb705d29303c8597d4f420f9030d5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/237340
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>

tools/bots/test_matrix.json

@@ -1774,6 +1774,29 @@
         }
       ]
     },
+    {
+      "builders": [
+        "vm-kernel-msvc-windows"
+      ],
+      "meta": {
+        "description": "This configuration builds the VM with MSVC."
+      },
+      "steps": [
+        {
+          "name": "build dart x64",
+          "script": "tools/build.py",
+          "arguments": [
+            "--mode=all",
+            "--arch=x64",
+            "--no-clang",
+            "--no-goma",
+            "dart_precompiled_runtime",
+            "gen_snapshot",
+            "runtime"
+          ]
+        }
+      ]
+    },
     {
       "builders": [
         "vm-kernel-linux-debug-simarm",
@@ -4175,4 +4198,4 @@
     "macos": "buildtools/mac-x64/clang/bin/llvm-symbolizer",
     "windows": "buildtools/win-x64/clang/bin/llvm-symbolizer.exe"
   }
-}
+}