[clang] [llvm] [PowerPC] Add builtin_cpu_is P11 support (PR #99550)

[David Tenty via cfe-commits]

================
@@ -103,6 +105,7 @@ PPC_CPU("ppc476",SYS_CALL,44,BUILTIN_PPC_FALSE,0)
 PPC_CPU("power8",SYS_CALL,45,USE_SYS_CONF,AIX_PPC8_VALUE)
 PPC_CPU("power9",SYS_CALL,46,USE_SYS_CONF,AIX_PPC9_VALUE)
 PPC_CPU("power10",SYS_CALL,47,USE_SYS_CONF,AIX_PPC10_VALUE)
+PPC_CPU("power11",SYS_CALL,48,USE_SYS_CONF,AIX_PPC11_VALUE)
----------------
daltenty wrote:

Note: we discussed this with the GCC folks, this is the unofficial value they are using as well.

https://github.com/llvm/llvm-project/pull/99550