unexpect field layout for sqlite3

[luoliwoshang]

struct sqlite3_index_info {
  int nConstraint;       
  struct sqlite3_index_constraint {
     int iColumn;           
     unsigned char op;       
     unsigned char usable;     
     int iTermOffset;        
  } *aConstraint;          
  int nOrderBy;            
  struct sqlite3_index_orderby {
     int iColumn;             
     unsigned char desc;    
  } *aOrderBy;            
  struct sqlite3_index_constraint_usage {
    int argvIndex;          
    unsigned char omit;      
  } *aConstraintUsage;
  int idxNum;             
  char *idxStr;              
  int needToFreeIdxStr;     
  int orderByConsumed;    
  double estimatedCost;          
  sqlite3_int64 estimatedRows;   
  int idxFlags;  
  sqlite3_uint64 colUsed;  
};

but only got

https://github.com/goplus/llcppg/blob/23c8a9e466c139c6af3ed9d7b19d072f5aa36852/_cmptest/testdata/sqlite3/3.49.1/sqlite3/sqlite3.go#L5643C1-L5657C2

https://github.com/goplus/llcppg/blob/23c8a9e466c139c6af3ed9d7b19d072f5aa36852/_cmptest/testdata/sqlite3/3.49.1/sqlite3/sqlite3.go#L5691C1-L5701C2

type IndexInfo struct {
	NConstraint      c.Int
	AConstraint      *IndexConstraint
	NOrderBy         c.Int
	AOrderBy         *IndexOrderby
	AConstraintUsage *IndexConstraintUsage
	IdxNum           c.Int
	IdxStr           *c.Char
	NeedToFreeIdxStr c.Int
	OrderByConsumed  c.Int
	EstimatedCost    c.Double
	EstimatedRows    Int64
	IdxFlags         c.Int
	ColUsed          Uint64
}
type IndexConstraint struct {
	Unused [8]uint8
}

type IndexOrderby struct {
	Unused [8]uint8
}

type IndexConstraintUsage struct {
	Unused [8]uint8
}

the named nested struct pointer actuall have type field not only a forward decl

[luoliwoshang]

support at #516