[llvm] [llvm-rc] Accept filenames provided as multiple string literals (PR #68881)

[Jacek Caban via llvm-commits]

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@@ -238,7 +238,27 @@ Expected<StringRef> RCParser::readString() {
 Expected<StringRef> RCParser::readFilename() {
   if (!isNextTokenKind(Kind::String) && !isNextTokenKind(Kind::Identifier))
     return getExpectedError("string");
-  return read().value();
+  const RCToken &Token = read();
+  StringRef Str = Token.value();
+  if (Token.kind() != Kind::String)
+    return Str;
+  while (isNextTokenKind(Kind::String)) {
+    const RCToken &NextToken = read();
+    StringRef Next = NextToken.value();
+    bool IsWide = Str.starts_with_insensitive("L");
+    if (IsWide)
+      Str = Str.drop_front();
+    if (Next.starts_with_insensitive("L"))
+      Next = Next.drop_front();
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cjacek wrote:

This could use `consume_front_insensitive`.

https://github.com/llvm/llvm-project/pull/68881