[clang] [llvm] [clang][llvm][aarch64][win] Add a clang flag and module attribute for import call optimization, and remove LLVM flag (PR #122831)

[Daniel Paoliello via llvm-commits]

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@@ -945,7 +944,7 @@ void AArch64AsmPrinter::emitEndOfAsmFile(Module &M) {
 
   // If import call optimization is enabled, emit the appropriate section.
   // We do this whether or not we recorded any import calls.
-  if (EnableImportCallOptimization && TT.isOSBinFormatCOFF()) {
+  if (EnableImportCallOptimization) {
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dpaoliello wrote:

`EnableImportCallOptimization` will only be set to true if we are targeting COFF (see `AArch64AsmPrinter::emitStartOfAsmFile`)

https://github.com/llvm/llvm-project/pull/122831