[llvm] RuntimeLibcalls: Fix missing const on getLibcallNames (PR #143074)

[Matt Arsenault via llvm-commits]

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@@ -68,10 +68,7 @@ struct RuntimeLibcallsInfo {
     return LibcallCallingConvs[Call];
   }
 
-  iterator_range<const char **> getLibcallNames() {
-    return llvm::make_range(LibcallRoutineNames,
-                            LibcallRoutineNames + RTLIB::UNKNOWN_LIBCALL);
-  }
+  ArrayRef<const char *> getLibcallNames() const { return LibcallRoutineNames; }
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arsenm wrote:

Not intentional, but it also doesn't really matter. Could drop_back, but it just appears as another null entry which uses have to tolerate anyway 

https://github.com/llvm/llvm-project/pull/143074