cgen: fix match

vlib/v/gen/cgen.v

@@ -513,8 +513,16 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write('$type_sym.name $tmp = ')
 			g.expr(it.cond)
 			g.writeln(';') // $it.blocks.len')
-			for branch in it.branches {
+			for j, branch in it.branches {
-				g.write('if ')
+				if j == it.branches.len - 1 {
+					// last block is an `else{}`
+					g.writeln('else {')
+				}
+				else {
+					if j > 0 {
+						g.write('else ')
+					}
+					g.write('if (')
 					for i, expr in branch.exprs {
 						g.write('$tmp == ')
 						g.expr(expr)
@@ -522,7 +530,8 @@ fn (g mut Gen) expr(node ast.Expr) {
 							g.write(' || ')
 						}
 					}
-				g.writeln('{')
+					g.writeln(') {')
+				}
 				g.stmts(branch.stmts)
 				g.writeln('}')
 			}

vlib/v/gen/tests/1.c

@@ -148,13 +148,15 @@ void println(string s) {
 void matches() {
 	int a = 100;
 	int tmp1 = a;
-	if tmp1 == 10{
+	if (tmp1 == 10) {
 		println(tos3("10"));
 
 	}
-	if tmp1 == 20{
+	else if (tmp1 == 20) {
 		int k = a + 1;
 
+	}
+	else {
 	}
 	;
 }

vlib/v/gen/tests/1.vv

@@ -147,6 +147,7 @@ fn matches() {
 		20 {
 			k := a + 1
 		}
+		else{}
 	}
 	/*
 	n := match a {