checker: report correct position for non-bool cond error (#8735)

vlib/v/checker/checker.v

@@ -4757,7 +4757,7 @@ pub fn (mut c Checker) if_expr(mut node ast.IfExpr) table.Type {
 				cond_typ := c.expr(branch.cond)
 				if cond_typ.idx() != table.bool_type_idx && !c.pref.translated {
 					typ_sym := c.table.get_type_symbol(cond_typ)
-					c.error('non-bool type `$typ_sym.name` used as if condition', branch.pos)
+					c.error('non-bool type `$typ_sym.name` used as if condition', branch.cond.position())
 				}
 			}
 		}

vlib/v/checker/tests/if_non_bool_cond.out

@@ -1,20 +1,20 @@
-vlib/v/checker/tests/if_non_bool_cond.vv:2:2: error: non-bool type `string` used as if condition
+vlib/v/checker/tests/if_non_bool_cond.vv:2:5: error: non-bool type `string` used as if condition
     1 | fn main() {
     2 |     if '10' {
-      |     ~~~~~~~
+      |        ~~~~
     3 |         println('10')
     4 |     }
-vlib/v/checker/tests/if_non_bool_cond.vv:6:2: error: non-bool type `int literal` used as if condition
+vlib/v/checker/tests/if_non_bool_cond.vv:6:5: error: non-bool type `int literal` used as if condition
     4 |     }
     5 | 
     6 |     if 5 {
-      |     ~~~~
+      |        ^
     7 |         println(5)
     8 |     }
-vlib/v/checker/tests/if_non_bool_cond.vv:10:2: error: non-bool type `void` used as if condition
+vlib/v/checker/tests/if_non_bool_cond.vv:10:5: error: non-bool type `void` used as if condition
     8 |     }
     9 | 
    10 |     if println('v') {
-      |     ~~~~~~~~~~~~~~~
+      |        ~~~~~~~~~~~~
    11 |         println('println')
    12 |     }