Exposed raw macro value source string.

Also fixed our editorconfig affecting LLVM.
(No idea how this wasn't a problem sooner.)

Author: PathogenDavid

ClangSharp.Pathogen/PathogenMacroInformation.cs

@@ -21,13 +21,16 @@ public unsafe readonly struct PathogenMacroInformation
         private readonly byte** ParameterNames;
         private readonly ulong* ParameterNameLengths;
         public readonly int TokenCount;
+        private readonly byte* _RawValueSourceString;
+        private readonly ulong _RawValueSourceStringLength;
 
         public string Name => Encoding.UTF8.GetString(_Name, checked((int)_NameLength));
         public bool WasUndefined => _WasUndefined != 0;
         public bool IsFunctionLike => _IsFunctionLike != 0;
         public bool IsBuiltinMacro => _IsBuiltinMacro != 0;
         public bool HasCommaPasting => _HasCommaPasting != 0;
         public bool IsUsedForHeaderGuard => _IsUsedForHeaderGuard != 0;
+        public string RawValueSourceString => Encoding.UTF8.GetString(_RawValueSourceString, checked((int)_RawValueSourceStringLength));
 
         public string GetParameterName(int index)
         {

external/.editorconfig

@@ -0,0 +1,2 @@
+# This file exists to protect LLVM from our editorconfig.
+root = true