[clang] [LinkerWrapper] Clean up options after proper forwarding (PR #126297)

[Nick Sarnie via cfe-commits]

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@@ -9220,13 +9220,24 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       for (StringRef Arg : LinkerArgs)
         CmdArgs.push_back(Args.MakeArgString(
             "--device-linker=" + TC->getTripleString() + "=" + Arg));
+
+      // Forward the LTO mode relying on the Driver's parsing.
+      if (C.getDriver().getOffloadLTOMode() == LTOK_Full)
+        CmdArgs.push_back(Args.MakeArgString(
+            "--device-compiler=" + TC->getTripleString() + "=-flto=full"));
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sarnex wrote:

this ends up getting passed to the `clang` call from `linkDevice`, where we are guaranteed we are not offloading (as in no two-phase compile) and we are compiling for the device offload triple right?

basically im confirming that we never need to pass `-foffload-lto` instead of `-flto`

https://github.com/llvm/llvm-project/pull/126297