Change `unreachable` with `panic`

core/image/png/png.odin

@@ -1002,7 +1002,7 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 				o16 = o16[out_image_channels:]
 			}
 		case:
-			unreachable("We should never seen # channels other than 1-4 inclusive.")
+			panic("We should never seen # channels other than 1-4 inclusive.")
 		}
 
 		img.pixels = t
@@ -1195,7 +1195,7 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 				o = o[out_image_channels:]
 			}
 		case:
-			unreachable("We should never seen # channels other than 1-4 inclusive.")
+			panic("We should never seen # channels other than 1-4 inclusive.")
 		}
 
 		img.pixels = t
@@ -1206,7 +1206,7 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
 			This may change if we ever don't expand 1, 2 and 4 bit images. But, those raw
 			returns will likely bypass this processing pipeline.
 		*/
-		unreachable("We should never see bit depths other than 8, 16 and 'Paletted' here.")
+		panic("We should never see bit depths other than 8, 16 and 'Paletted' here.")
 	}
 
 	return img, nil