[llvm] RuntimeLibcalls: Add bitset for available libcalls (PR #150869)

[Matt Arsenault via llvm-commits]

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@@ -53,8 +54,22 @@ static inline auto libcall_impls() {
   return enum_seq(static_cast<RTLIB::LibcallImpl>(1), RTLIB::NumLibcallImpls);
 }
 
+/// Manage a bitset representing the list of available libcalls for a module.
+class LibcallImplBitset : public Bitset<RTLIB::NumLibcallImpls> {
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arsenm wrote:

This is using the protected constructor to directly set the array elements. Otherwise I'd have to print a gigantic initializer list per bit 

https://github.com/llvm/llvm-project/pull/150869