[llvm] Reserve R9 on armv6 iOS 2.x (PR #150835)

[Jon Roelofs via llvm-commits]

================
@@ -6,12 +6,19 @@
 ; RUN: llc <%s -mtriple=arm-none-eabi --frame-pointer=all 2>&1 \
 ; RUN:   | FileCheck %s -check-prefix=NO_FP_ELIM
 
+; RUN: llc <%s -mtriple=armv6k-apple-ios2 2>&1 | FileCheck %s -check-prefix=IOS2
----------------
jroelofs wrote:

```suggestion
; RUN: llc <%s -mtriple=armv6-apple-ios2 2>&1 | FileCheck %s -check-prefix=IOS2
; RUN: llc <%s -mtriple=armv6k-apple-ios2 2>&1 | FileCheck %s -check-prefix=IOS2
```

https://github.com/llvm/llvm-project/pull/150835