[lld] [ELF] Added `struct Token` and changed `next()` and `peek()` to return Token (PR #100180)

[Hongyu Chen via llvm-commits]

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@@ -90,6 +90,22 @@ std::string ScriptLexer::getCurrentLocation() {
   return (filename + ":" + Twine(getLineNumber())).str();
 }
 
+std::string ScriptLexer::joinTokens(size_t begin, size_t end) {
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yugier wrote:

This function may not be needed once the Lexer can be fully stateful one. I plan to keep this for temporary resolution for printing out StringRef from `struct Token`

https://github.com/llvm/llvm-project/pull/100180