build: Clean up post-build copy of Windows DLLs (#31092)

* build: Clean up post-build copy of Windows DLLs

- No longer use vcvarsall.bat at all. Instead find the Windows SDK
  directory by looking in the registry.
- Split logic for copying Windows dependencies into its own function and
  do some minor clean up, such as collecting all MSVC functionality into
  visual_studio.py.
- Remove support for Visual Studio 2015 and Visual Studio 2017.

This is a preparatory change in order to support Visual Studio 2022.

* More cleanup of the code

python/servo/visual_studio.py

@@ -0,0 +1,149 @@
+# Copyright 2024 The Servo Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+import dataclasses
+import json
+import os
+import subprocess
+import sys
+from typing import List
+
+import servo.platform
+
+
+@dataclasses.dataclass(kw_only=True)
+class VisualStudioInstallation:
+    version_number: str
+    installation_path: str
+    vc_install_path: str
+
+
+def find_highest_msvc_version_ext():
+    """Try to find the MSVC installation with the `vswhere.exe` tool. The results
+    are sorted with newer versions first."""
+    def vswhere(args):
+        program_files = (os.environ.get('PROGRAMFILES(X86)')
+                         or os.environ.get('PROGRAMFILES'))
+        if not program_files:
+            return []
+        vswhere = os.path.join(program_files, 'Microsoft Visual Studio', 'Installer', 'vswhere.exe')
+        if not os.path.exists(vswhere):
+            return []
+        output = subprocess.check_output([vswhere, '-format', 'json'] + args).decode(errors='ignore')
+        return json.loads(output)
+
+    for install in vswhere(['-products', '*',
+                            '-requires', 'Microsoft.VisualStudio.Component.VC.Tools.x86.x64',
+                            '-requires', 'Microsoft.VisualStudio.Component.Windows10SDK']):
+        version = install['installationVersion'].split('.')[0] + '.0'
+        yield (install['installationPath'], version)
+
+
+def find_highest_msvc_version():
+    prog_files = os.environ.get("ProgramFiles(x86)")
+
+    # TODO(mrobinson): Add support for Visual Studio 2022.
+    vs_versions = {
+        "2019": "16.0",
+    }
+
+    for (version, version_number) in vs_versions.items():
+        for edition in ["Enterprise", "Professional", "Community", "BuildTools"]:
+            vsinstalldir = os.path.join(prog_files, "Microsoft Visual Studio", version, edition)
+            if os.path.exists(vsinstalldir):
+                return (vsinstalldir, version_number)
+
+    versions = sorted(find_highest_msvc_version_ext(), key=lambda tup: float(tup[1]))
+    if not versions:
+        print("Can't find a Visual Studio installation. "
+              "Please set the VSINSTALLDIR and VisualStudioVersion environment variables")
+        sys.exit(1)
+    return versions[0]
+
+
+def find_msvc() -> VisualStudioInstallation:
+    vsinstalldir = os.environ.get('VSINSTALLDIR')
+    version_number = os.environ.get('VisualStudioVersion')
+    if not vsinstalldir or not version_number:
+        (vsinstalldir, version_number) = find_highest_msvc_version()
+
+    vc_install_path = os.environ.get("VCINSTALLDIR", os.path.join(vsinstalldir, "VC"))
+    if not os.path.exists(vc_install_path):
+        print(f"Can't find Visual C++ {version_number} installation at {vc_install_path}")
+        sys.exit(1)
+
+    return VisualStudioInstallation(
+        version_number=version_number,
+        installation_path=vsinstalldir,
+        vc_install_path=vc_install_path,
+    )
+
+
+def find_windows_sdk_installation_path(vs_platform: str) -> str:
+    """Try to find the Windows SDK installation path using the Windows registry.
+    Raises an Exception if the path cannot be found in the registry."""
+
+    # This module must be imported here, because other platforms also
+    # load this file and the module is platform-specific.
+    import winreg
+
+    # This is based on the advice from
+    # https://stackoverflow.com/questions/35119223/how-to-programmatically-detect-and-locate-the-windows-10-sdk
+    key_path = r'SOFTWARE\Wow6432Node\Microsoft\Microsoft SDKs\Windows\v10.0'
+    try:
+        with winreg.OpenKeyEx(winreg.HKEY_LOCAL_MACHINE, key_path) as key:
+            path = str(winreg.QueryValueEx(key, "InstallationFolder")[0])
+            return os.path.join(path, "Redist", "ucrt", "DLLs", vs_platform)
+    except FileNotFoundError:
+        raise Exception(f"Couldn't find Windows SDK installation path in registry at path ({key_path})")
+
+
+def find_msvc_redist_dirs(target: str) -> List[str]:
+    assert 'windows' in servo.platform.host_triple()
+
+    installation = find_msvc()
+    msvc_redist_dir = None
+    vs_platforms = {
+        "x86_64": "x64",
+        "i686": "x86",
+        "aarch64": "arm64",
+    }
+    target_arch = target.split('-')[0]
+    vs_platform = vs_platforms[target_arch]
+
+    redist_dir = os.path.join(installation.vc_install_path, "Redist", "MSVC")
+    if not os.path.isdir(redist_dir):
+        raise Exception(f"Couldn't locate MSVC redistributable directory {redist_dir}")
+
+    for p in os.listdir(redist_dir)[::-1]:
+        redist_path = os.path.join(redist_dir, p)
+        for v in ["VC141", "VC142", "VC150", "VC160"]:
+            # there are two possible paths
+            # `x64\Microsoft.VC*.CRT` or `onecore\x64\Microsoft.VC*.CRT`
+            redist1 = os.path.join(redist_path, vs_platform, "Microsoft.{}.CRT".format(v))
+            redist2 = os.path.join(redist_path, "onecore", vs_platform, "Microsoft.{}.CRT".format(v))
+            if os.path.isdir(redist1):
+                msvc_redist_dir = redist1
+                break
+            elif os.path.isdir(redist2):
+                msvc_redist_dir = redist2
+                break
+        if msvc_redist_dir:
+            break
+
+    if not msvc_redist_dir:
+        print("Couldn't locate MSVC redistributable directory")
+        sys.exit(1)
+
+    redist_dirs = [
+        msvc_redist_dir,
+        find_windows_sdk_installation_path(vs_platform)
+    ]
+
+    return redist_dirs