Move NPred in parse.c and decrease it

This now only limits the number of arguments when parsing the input SSA,
which is usually a small fixed size (depending on the frontend).

all.h

@@ -32,7 +32,6 @@ typedef struct Target Target;
 
 enum {
 	NString = 64,
-	NPred   = 127,
 	NIns    = 1 << 20,
 	NAlign  = 3,
 	NField  = 32,

parse.c

@@ -102,6 +102,8 @@ static char *kwmap[Ntok] = {
 };
 
 enum {
+	NPred = 63,
+
 	TMask = 16383, /* for temps hash */
 	BMask = 8191, /* for blocks hash */