checker: Revert part of small_unsigned == signed (#13967) (#14075)

`gcc -W` doesn't error for e.g. u16 == i32, only for u32 == i16.
Any u16 value can fit in an i32.

vlib/bitfield/bitfield_test.v

@@ -161,7 +161,7 @@ fn test_bf_from_str() {
 	output := bitfield.from_str(input)
 	mut result := 1
 	for i in 0 .. len {
-		if input[i] != u8(output.get_bit(i)) + 48 {
+		if input[i] != output.get_bit(i) + 48 {
 			result = 0
 		}
 	}

vlib/term/ui/input_windows.c.v

@@ -288,8 +288,8 @@ fn (mut ctx Context) parse_events() {
 				if !C.GetConsoleScreenBufferInfo(ctx.stdout_handle, &sb) {
 					panic('could not get screenbuffer info')
 				}
-				w := int(sb.srWindow.Right - sb.srWindow.Left + 1)
+				w := sb.srWindow.Right - sb.srWindow.Left + 1
-				h := int(sb.srWindow.Bottom - sb.srWindow.Top + 1)
+				h := sb.srWindow.Bottom - sb.srWindow.Top + 1
 				utf8 := '($ctx.window_width, $ctx.window_height) -> ($w, $h)'
 				if w != ctx.window_width || h != ctx.window_height {
 					ctx.window_width, ctx.window_height = w, h

vlib/v/checker/checker.v

@@ -639,15 +639,6 @@ pub fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 						rt := c.table.sym(right_type).name
 						c.error('negative value cannot be compared with `$rt`', node.left.pos)
 					}
-				} else if is_left_type_signed != is_right_type_signed
-					&& left_type.flip_signedness() != right_type {
-					// prevent e.g. `u16(-1) == int(-1)` which is false in C
-					if (is_right_type_signed && left_type in ast.int_promoted_type_idxs)
-						|| (is_left_type_signed && right_type in ast.int_promoted_type_idxs) {
-						lt := c.table.sym(left_type).name
-						rt := c.table.sym(right_type).name
-						c.error('`$lt` cannot be compared with `$rt`', node.pos)
-					}
 				}
 			}
 		}

vlib/v/checker/tests/compare_unsigned_signed.out

@@ -17,24 +17,10 @@ vlib/v/checker/tests/compare_unsigned_signed.vv:10:16: error: `u8` cannot be com
    10 |     _ = u8(-1) == -1 // false!
       |                   ~~
    11 |     _ = -1 == u16(-1) // false!
-   12 |
+   12 | }
 vlib/v/checker/tests/compare_unsigned_signed.vv:11:6: error: negative value cannot be compared with `u16`
     9 |     // unsigned == literal
    10 |     _ = u8(-1) == -1 // false!
    11 |     _ = -1 == u16(-1) // false!
       |         ~~
-   12 | 
+   12 | }
-   13 |     // unsigned == signed
-vlib/v/checker/tests/compare_unsigned_signed.vv:14:14: error: `u16` cannot be compared with `int`
-   12 | 
-   13 |     // unsigned == signed
-   14 |     _ = u16(-1) == int(-1)
-      |                 ~~
-   15 |     _ = int(-1) != u8(-1)
-   16 | }
-vlib/v/checker/tests/compare_unsigned_signed.vv:15:14: error: `int` cannot be compared with `u8`
-   13 |     // unsigned == signed
-   14 |     _ = u16(-1) == int(-1)
-   15 |     _ = int(-1) != u8(-1)
-      |                 ~~
-   16 | }

vlib/v/checker/tests/compare_unsigned_signed.vv

@@ -9,8 +9,4 @@ fn main() {
 	// unsigned == literal
 	_ = u8(-1) == -1 // false!
 	_ = -1 == u16(-1) // false!
-
-	// unsigned == signed
-	_ = u16(-1) == int(-1)
-	_ = int(-1) != u8(-1)
 }

vlib/x/ttf/render_bmp.v

@@ -778,7 +778,7 @@ pub fn (mut bmp BitMap) draw_glyph(index u16) (int, int) {
 			}
 		}
 
-		if count == int(glyph.contour_ends[c]) {
+		if count == glyph.contour_ends[c] {
 			// dprintln("count == glyph.contour_ends[count]")
 			if s == 2 { // final point was off-curve. connect to start