This patch implements builtins for the following prototypes:

vector signed char vec_permx (vector signed char, vector signed char, vector unsigned char, const int);

vector unsigned char vec_permx (vector unsigned char, vector unsigned char, vector unsigned char, const int);

vector signed short vec_permx (vector signed short, vector signed short, vector unsigned char, const int);

vector unsigned short vec_permx (vector unsigned short, vector unsigned short, vector unsigned char, const int);

vector signed int vec_permx (vector signed int, vector signed int, vector unsigned char, const int);

vector unsigned int vec_permx (vector unsigned int, vector unsigned int, vector unsigned char, const int);

vector signed long long vec_permx (vector signed long long, vector signed long long, vector unsigned char, const int);

vector unsigned long long vec_permx (vector unsigned long long, vector unsigned long long, vector unsigned char, const int);

vector float vec_permx (vector float, vector float, vector unsigned char, const int);

vector double vec_permx (vector double, vector double, vector unsigned char, const int);

“Depends on D82859”