update_test_checks: support more arm64_32-apple-watchos triples

Having the version in `get_run_handlers` meant that a RUN line without the
version in it would not match, and therefore UTC would generate a useless
catch-all check of the form:

```
;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
; CHECK: {{.*}}
```

This patch also adds `arm64_32` as a base-level run handler, and assumes it
will always apply to a darwin target (which is currently the case for all
arm64_32-* triples I see in tree currently).

Author: jroelofs

llvm/test/CodeGen/AArch64/lower-ptrmask-arm64_32.ll

@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
-; RUN: llc -mtriple=arm64_32-apple-watchos2.0.0 %s -o - | FileCheck %s
+; RUN: llc -mtriple=arm64_32-apple-watchos %s -o - | FileCheck %s
 
 define ptr @issue94075(ptr %p) {
 ; CHECK-LABEL: issue94075:

llvm/utils/UpdateTestChecks/asm.py

@@ -534,8 +534,9 @@ def get_run_handler(triple):
         "i686": (scrub_asm_x86, ASM_FUNCTION_X86_RE),
         "x86": (scrub_asm_x86, ASM_FUNCTION_X86_RE),
         "i386": (scrub_asm_x86, ASM_FUNCTION_X86_RE),
+        "arm64_32": (scrub_asm_arm_eabi, ASM_FUNCTION_AARCH64_DARWIN_RE),
         "arm64_32-apple-ios": (scrub_asm_arm_eabi, ASM_FUNCTION_AARCH64_DARWIN_RE),
-        "arm64_32-apple-watchos2.0.0": (
+        "arm64_32-apple-watchos": (
             scrub_asm_arm_eabi,
             ASM_FUNCTION_AARCH64_DARWIN_RE,
         ),