llvmjit: Remove unnecessary types

These types were added in fb46ac26fe but hasn't been used, so
remove until there is a need for them.

Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/20221101055132.pjjsvlkeo4stbjkq@awork3.anarazel.de

src/backend/jit/llvm/llvmjit.c

@@ -61,23 +61,12 @@ LLVMTypeRef TypeParamBool;
 LLVMTypeRef TypeStorageBool;
 LLVMTypeRef TypePGFunction;
 LLVMTypeRef StructNullableDatum;
-LLVMTypeRef StructHeapTupleFieldsField3;
-LLVMTypeRef StructHeapTupleFields;
-LLVMTypeRef StructHeapTupleHeaderData;
-LLVMTypeRef StructHeapTupleDataChoice;
 LLVMTypeRef StructHeapTupleData;
-LLVMTypeRef StructMinimalTupleData;
-LLVMTypeRef StructItemPointerData;
-LLVMTypeRef StructBlockId;
-LLVMTypeRef StructFormPgAttribute;
-LLVMTypeRef StructTupleConstr;
 LLVMTypeRef StructTupleDescData;
 LLVMTypeRef StructTupleTableSlot;
 LLVMTypeRef StructHeapTupleTableSlot;
 LLVMTypeRef StructMinimalTupleTableSlot;
 LLVMTypeRef StructMemoryContextData;
-LLVMTypeRef StructPGFinfoRecord;
-LLVMTypeRef StructFmgrInfo;
 LLVMTypeRef StructFunctionCallInfoData;
 LLVMTypeRef StructExprContext;
 LLVMTypeRef StructExprEvalStep;