Configure clangd for the native Windows x86 toolchain

.clangd

@@ -1,2 +1,4 @@
 CompileFlags:
   CompilationDatabase: build/editor-x86
+  Add: [--driver-mode=cl, --target=i686-pc-windows-msvc, -fms-compatibility-version=19.29]
+  Remove: [/FS, /O2, /Ob2]

configure-clangd.ps1

@@ -0,0 +1,58 @@
+[CmdletBinding()]
+param()
+
+$ErrorActionPreference = 'Stop'
+$root = $PSScriptRoot.Replace('\', '/')
+$project = Get-Content -LiteralPath "$PSScriptRoot/decomp.json" -Raw | ConvertFrom-Json
+$compile = Get-Content -LiteralPath "$PSScriptRoot/$($project.compileCommands)" -Raw | ConvertFrom-Json
+$workspace = Get-Content -LiteralPath "$PSScriptRoot/.td/config.json" -Raw | ConvertFrom-Json
+$runner = $workspace.runners.PSObject.Properties[$project.toolchain].Value
+
+if (-not $runner -or $runner.type -ne 'native' -or -not $runner.toolchainRoot) {
+  throw "clangd configuration requires this workspace's native Windows toolchain."
+}
+
+$toolchain = $runner.toolchainRoot.Replace('\', '/')
+$compiler = $compile.compiler.Replace('${TC}', $toolchain).Replace('${SRC}', $root)
+
+if (-not (Test-Path -LiteralPath $compiler -PathType Leaf)) {
+  throw "Configured compiler not found: $compiler"
+}
+
+$systemIncludes = @($compile.env.INCLUDE.Replace('${TC}', $toolchain).Replace('${SRC}', $root).Split(';') | Where-Object { $_ })
+
+foreach ($include in $systemIncludes) {
+  if (-not (Test-Path -LiteralPath $include -PathType Container)) {
+    throw "Configured include directory not found: $include"
+  }
+}
+
+$commands = @(
+  foreach ($unit in $compile.units.PSObject.Properties) {
+    $file = "$root/$($unit.Name)"
+
+    if (-not (Test-Path -LiteralPath $file -PathType Leaf)) {
+      throw "Configured source file not found: $file"
+    }
+
+    $arguments = @($compiler)
+    $arguments += @($compile.shapes[[int]$unit.Value] | ForEach-Object {
+      $_.Replace('${TC}', $toolchain).Replace('${SRC}', $root)
+    })
+    $arguments += @($systemIncludes | ForEach-Object { "/imsvc$_" })
+    $arguments += $file
+
+    [ordered]@{
+      directory = $root
+      file = $file
+      arguments = $arguments
+    }
+  }
+)
+
+$outputDirectory = Join-Path $PSScriptRoot 'build/editor-x86'
+[void](New-Item -ItemType Directory -Path $outputDirectory -Force)
+$output = Join-Path $outputDirectory 'compile_commands.json'
+$json = ConvertTo-Json -InputObject $commands -Depth 6
+[System.IO.File]::WriteAllText($output, $json + "`n", [System.Text.UTF8Encoding]::new($false))
+Write-Output "Generated $($commands.Count) clangd compilation commands: $output"