lang: Allow inline statements again

[karpfediem]

With the changes in #919 we now require a newline in the last occuring/final stmt token.

This means as a concrete example this won't parse anymore:

❯ build/mgmt-linux-amd64 run lang 'print "hello" { msg => "world", }' --no-network --converged-timeout 1
This is: mgmt, version: 1.0.2-168-g423add81
Copyright (C) James Shubin and the project contributors
Written by James Shubin <james@shubin.ca> and the project contributors
21:22:22 main: start: 1779045742833061284
21:22:22 cli: lang: lexing/parsing...
21:22:22 main: goodbye!
cli parse error: could not generate AST: parser: `syntax error: unexpected $end, expecting NEWLINE` @1:1

It now needs to have a newline at the end

❯ build/mgmt-linux-amd64 run lang 'print "hello" { msg => "world", }
' --no-network --converged-timeout 1

There is already a likely useful/related commented-out top: prog stmt branch here

mgmt/lang/parser/parser.y

Lines 162 to 180 in c7acc75

	// Allow a final stmt without a trailing newline (e.g. input that
	// doesn't end with `\n`). A NEWLINE here would be handled by the
	// `prog stmt NEWLINE` rule below, so this only fires at the $end.
	/*
	| prog stmt
	{
	posLast(yylex, yyDollar) // our pos
	if stmt, ok := $1.stmt.(*ast.StmtProg); ok {
	stmts := stmt.Body
	stmts = append(stmts, $2.stmt)
	prog := &ast.StmtProg{
	Body: stmts,
	}
	locate(yylex, $1, yyDollar[len(yyDollar)-1], prog)
	lp := cast(yylex)
	lp.ast = prog
	}
	}
	*/

[purpleidea]

There is already a likely useful/related commented-out top: prog stmt branch here

Indeed, I left that in in case I needed to add it. I didn't find an easier way. TL;DR: i feel that logically any program should bring it's own newline, but it was hard to add it everywhere so I left out a few places. I did add in one scenario. More pending I guess.

[purpleidea]

In any case this issue is legit, and it probably needs both a test and a small patch. My guess is we need to add a newline at the end if none exists in the right place(s) in https://github.com/purpleidea/mgmt/blob/master/lang/inputs/inputs.go