checker: simplify type sizeof check and fix c2v globals

vlib/v/checker/check_types.v

@@ -15,10 +15,13 @@ pub fn (mut c Checker) check_types(got ast.Type, expected ast.Type) bool {
 		if expected == ast.byteptr_type {
 			return true
 		}
+		if expected == ast.voidptr_type {
+			return true
+		}
 		if expected.is_any_kind_of_pointer() { //&& !got.is_any_kind_of_pointer() {
 			// Allow `int` as `&i8` etc in C code.
-			// deref := expected.deref()
-			deref := expected.set_nr_muls(0)
+			deref := expected.deref()
+			// deref := expected.set_nr_muls(0)
 			got_sym := c.table.sym(got)
 			if deref.is_number() && (got_sym.is_number() || got_sym.kind == .enum_) {
 				return true

vlib/v/parser/expr.v

@@ -197,8 +197,11 @@ pub fn (mut p Parser) check_expr(precedence int) ?ast.Expr {
 			pos := p.tok.position()
 			is_known_var := p.mark_var_as_used(p.tok.lit)
 				|| p.table.global_scope.known_const(p.mod + '.' + p.tok.lit)
+			//|| p.table.known_fn(p.mod + '.' + p.tok.lit)
 			// assume `mod.` prefix leads to a type
-			if is_known_var || !(p.known_import(p.tok.lit) || p.tok.kind.is_start_of_type()) {
+			is_type := p.known_import(p.tok.lit) || p.tok.kind.is_start_of_type()
+				|| (p.tok.lit.len > 0 && p.tok.lit[0].is_capital())
+			if is_known_var || !is_type {
 				expr := p.expr(0)
 				if is_reftype {
 					node = ast.IsRefType{

vlib/v/parser/parser.v

@@ -3596,6 +3596,7 @@ fn (mut p Parser) rewind_scanner_to_current_token_in_new_mode() {
 	}
 }
 
+// returns true if `varname` is known
 pub fn (mut p Parser) mark_var_as_used(varname string) bool {
 	if obj := p.scope.find(varname) {
 		match mut obj {
@@ -3603,6 +3604,10 @@ pub fn (mut p Parser) mark_var_as_used(varname string) bool {
 				obj.is_used = true
 				return true
 			}
+			ast.GlobalField {
+				// obj.is_used = true
+				return true
+			}
 			// ast.ConstField {
 			// return true
 			//}