[llvm] RuntimeLibcalls: Mostly move x86 configuration into tablegen (PR #148575)

[Matt Arsenault via llvm-commits]

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@@ -1151,7 +1187,10 @@ def isAArch64_ILP64  : RuntimeLibcallPredicate<"TT.isAArch64(64)">;
 
 def AArch64SystemLibrary : SystemRuntimeLibrary<
   isAArch64_ExceptArm64EC,
-  (add DefaultRuntimeLibcallImpls,
+  (add Win64DefaultLibcallImpls,
+       LibcallImpls<(add __powisf2, __powidf2), isNotOSMSVCRT>,
+       LibmHasFrexpF32, LibmHasLdexpF32,
+       LibmHasFrexpF128, LibmHasLdexpF128,
        AArch64LibcallImpls,
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arsenm wrote:

Because Win64DefaultLibcallImpls is the subset supported by windows. Everything else is additive for different not windows 

https://github.com/llvm/llvm-project/pull/148575