[clang] [Clang] Rework LTO mode selection to be a Toolchain property (PR #201155)

[Joseph Huber via cfe-commits]

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@@ -55,12 +55,7 @@ class JobAction;
 class ToolChain;
 
 /// Describes the kind of LTO mode selected via -f(no-)?lto(=.*)? options.
-enum LTOKind {
-  LTOK_None,
-  LTOK_Full,
-  LTOK_Thin,
-  LTOK_Unknown
-};
+enum LTOKind : int { LTOK_None, LTOK_Full, LTOK_Thin, LTOK_Unknown };
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jhuber6 wrote:

Figured this was less delta in the PR, I was going to do some more cleanups in the future but wanted this to be as NFC as possible.

https://github.com/llvm/llvm-project/pull/201155