[flang] [clang] [flang][Driver] Let the linker fail on multiple definitions of main() (PR #73124)

[Kiran Chandramohan via cfe-commits]

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@@ -122,6 +122,7 @@
 # the build directory holding that tool.
 tools = [
     ToolSubst("%flang", command=FindTool("flang-new"), unresolved="fatal"),
+    ToolSubst("%clang", command=FindTool("clang"), unresolved="fatal"),
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kiranchandramohan wrote:

Remove this if using the system compiler works.

https://github.com/llvm/llvm-project/pull/73124