GlobalISel: Add typeIsNot LegalityPredicate

[arsenm]

Summary

This allows sorting the legal/custom rules first as is recommended

[paquette]

LGTM

[arsenm]

5174e7b443d815df6707addbd4fe172418d6f4a2

llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h

Predicate any(Predicate P0, Predicate P1) {
   };
 }
 /// True iff any given predicates are true.
 template<typename Predicate, typename... Args>
 Predicate any(Predicate P0, Predicate P1, Args... args) {
   return any(any(P0, P1), args...);
 }
 
-/// True iff the given type index is the specified types.
+/// True iff the given type index is the specified type.
 LegalityPredicate typeIs(unsigned TypeIdx, LLT TypesInit);
 /// True iff the given type index is one of the specified types.
 LegalityPredicate typeInSet(unsigned TypeIdx,
                             std::initializer_list<LLT> TypesInit);
+
+/// True iff the given type index is not the specified type.
+inline LegalityPredicate typeIsNot(unsigned TypeIdx, LLT Type) {
+  return [=](const LegalityQuery &Query) {
+           return Query.Types[TypeIdx] != Type;
+         };
+}
+
 /// True iff the given types for the given pair of type indexes is one of the
 /// specified type pairs.
 LegalityPredicate
 typePairInSet(unsigned TypeIdx0, unsigned TypeIdx1,
               std::initializer_list<std::pair<LLT, LLT>> TypesInit);
 /// True iff the given types for the given pair of type indexes is one of the
 /// specified type pairs.
 LegalityPredicate typePairAndMemDescInSet(

llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp

AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
   setAction({G_FRAME_INDEX, PrivatePtr}, Legal);
 
   // If the amount is divergent, we have to do a wave reduction to get the
   // maximum value, so this is expanded during RegBankSelect.
   getActionDefinitionsBuilder(G_DYN_STACKALLOC)
     .legalFor({{PrivatePtr, S32}});
 
   getActionDefinitionsBuilder(G_GLOBAL_VALUE)
-    .unsupportedFor({PrivatePtr})
-    .custom();
+    .customIf(typeIsNot(0, PrivatePtr));
+
   setAction({G_BLOCK_ADDR, CodePtr}, Legal);
 
   auto &FPOpActions = getActionDefinitionsBuilder(
     { G_FADD, G_FMUL, G_FMA, G_FCANONICALIZE})
     .legalFor({S32, S64});
   auto &TrigActions = getActionDefinitionsBuilder({G_FSIN, G_FCOS})
     .customFor({S32, S64});
   auto &FDIVActions = getActionDefinitionsBuilder(G_FDIV)