[llvm] [llvm-dlltool] Use EXPORTAS name type for renamed imports on ARM64EC. (PR #99346)

[Jacek Caban via llvm-commits]

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@@ -53,3 +66,8 @@ EXPORTS
 LIBRARY test.dll
 EXPORTS
     otherfunc
+
+#--- test3.def
+LIBRARY test.dll
+EXPORTS
+    func == efunc
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cjacek wrote:

Good point, that's a more interesting case. I pushed more tests.

FWIW, we were not using weak alias path in that test, but for a wrong reason: we were comparing mangled name to demangled one (and generally skipping mangling fixup). That's no longer a problem with this PR as there are no deferred on EC target. Looking at it again we should probably take `ExportName` into account when filling `RegularImports` map anyway for corner cases with a mixture of mingw-style aliases and explicit EXPORTAS .

https://github.com/llvm/llvm-project/pull/99346