stage2+stage1: remove type parameter from bit builtins

Closes ziglang#12529
Closes ziglang#12511
Closes ziglang#6835

Author: Vexu

compile_errors/errors_in_for_loop_bodies_are_propagated.zig

@@ -1,10 +1,10 @@
 pub export fn entry() void {
     var arr: [100]u8 = undefined;
-    for (arr) |bits| _ = @popCount(bits);
+    for (arr) |bits| _ = @popCount(u8, bits);
 }
 
 // error
 // backend=stage2
 // target=native
 //
-// :3:26: error: expected 2 arguments, found 1
+// :3:26: error: expected 1 argument, found 2

compile_errors/popCount-non-integer.zig

@@ -1,9 +1,9 @@
 export fn entry(x: f32) u32 {
-    return @popCount(f32, x);
+    return @popCount(x);
 }
 
 // error
 // backend=stage2
 // target=native
 //
-// :2:27: error: expected integer or vector, found 'f32'
+// :2:22: error: expected integer or vector, found 'f32'