[llvm] Add Apple M4 host detection (PR #117530)

[Jon Roelofs via llvm-commits]

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@@ -1494,15 +1539,24 @@ StringRef sys::getHostCPUName() {
     return "apple-a12";
   case CPUFAMILY_ARM_LIGHTNING_THUNDER:
     return "apple-a13";
-  case CPUFAMILY_ARM_FIRESTORM_ICESTORM:
+  case CPUFAMILY_ARM_FIRESTORM_ICESTORM: // A14 / M1
     return "apple-m1";
-  case CPUFAMILY_ARM_BLIZZARD_AVALANCHE:
+  case CPUFAMILY_ARM_BLIZZARD_AVALANCHE: // A15 / M2
     return "apple-m2";
-  case CPUFAMILY_ARM_EVEREST_SAWTOOTH:
+  case CPUFAMILY_ARM_EVEREST_SAWTOOTH: // A16
+  case CPUFAMILY_ARM_IBIZA:            // M3
+  case CPUFAMILY_ARM_PALMA:            // M3 Max
+  case CPUFAMILY_ARM_COLL:             // A17
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jroelofs wrote:

`apple-a17` is it's own thing, this shouldn't get merged with `apple-m3`. See the `ProcessorAlias<>` entries in `AArch64Processors.td`

https://github.com/llvm/llvm-project/pull/117530