parser: Update from go tool yacc into goyacc

Since Go 1.8 removed the go tool yacc command,
we should update it to use goyacc

Author: corona10

parser/grammar_data_test.go

@@ -260,6 +260,9 @@ var grammarTestData = []struct {
 	{"a, b = *a", "exec", "Module(body=[Assign(targets=[Tuple(elts=[Name(id='a', ctx=Store()), Name(id='b', ctx=Store())], ctx=Store())], value=Starred(value=Name(id='a', ctx=Load()), ctx=Load()))])", nil, ""},
 	{"a = yield a", "exec", "Module(body=[Assign(targets=[Name(id='a', ctx=Store())], value=Yield(value=Name(id='a', ctx=Load())))])", nil, ""},
 	{"a.b = 1", "exec", "Module(body=[Assign(targets=[Attribute(value=Name(id='a', ctx=Load()), attr='b', ctx=Store())], value=Num(n=1))])", nil, ""},
+	{"[e for e in [1, 2, 3]] = 3", "exec", "", py.SyntaxError, "can't assign to list comprehension"},
+	{"{e for e in [1, 2, 3]} = 3", "exec", "", py.SyntaxError, "can't assign to set comprehension"},
+	{"{e: e**2 for e in [1, 2, 3]} = 3", "exec", "", py.SyntaxError, "can't assign to dict comprehension"},
 	{"f() = 1", "exec", "", py.SyntaxError, "can't assign to function call"},
 	{"lambda: x = 1", "exec", "", py.SyntaxError, "can't assign to lambda"},
 	{"(a + b) = 1", "exec", "", py.SyntaxError, "can't assign to operator"},

parser/parser.go

@@ -7,5 +7,5 @@
 //      % go generate
 //      % go build
 
-//go:generate go tool yacc -v y.output grammar.y
+//go:generate goyacc -v y.output grammar.y
 package parser