[llvm] [offload] Unset `-march` when building GPU libraries (PR #136442)

[Shilei Tian via llvm-commits]

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@@ -137,9 +137,9 @@ function(compileDeviceRTLLibrary target_name target_triple)
     BUILD_RPATH ""
     INSTALL_RPATH ""
     RUNTIME_OUTPUT_NAME libomptarget-${target_name}.bc)
-  target_compile_options(libomptarget-${target_name} PRIVATE "--target=${target_triple}")
+  target_compile_options(libomptarget-${target_name} PRIVATE "--target=${target_triple}" "-march=")
   target_link_options(libomptarget-${target_name} PRIVATE "--target=${target_triple}"
-                      "-r" "-nostdlib" "-flto" "-Wl,--lto-emit-llvm")
+                      "-r" "-nostdlib" "-flto" "-Wl,--lto-emit-llvm" "-march=")
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shiltian wrote:

I vaguely remember we used to have an empty march before but it must have been removed at one point.

https://github.com/llvm/llvm-project/pull/136442