x/tools/present: remove unused code

Found with honnef.co/go/tools/cmd/unused.

Change-Id: Iabfa1e9926e097ba11d1db0a2d785fec70ce3997
Reviewed-on: https://go-review.googlesource.com/37609
Reviewed-by: Alan Donovan <adonovan@google.com>

present/code.go

@@ -265,44 +265,3 @@ func parseArgs(name string, line int, args []string) (res []interface{}, err err
 	}
 	return
 }
-
-// parseArg returns the integer or string value of the argument and tells which it is.
-func parseArg(arg interface{}, max int) (ival int, sval string, isInt bool, err error) {
-	switch n := arg.(type) {
-	case int:
-		if n <= 0 || n > max {
-			return 0, "", false, fmt.Errorf("%d is out of range", n)
-		}
-		return n, "", true, nil
-	case string:
-		return 0, n, false, nil
-	}
-	return 0, "", false, fmt.Errorf("unrecognized argument %v type %T", arg, arg)
-}
-
-// match identifies the input line that matches the pattern in a code invocation.
-// If start>0, match lines starting there rather than at the beginning.
-// The return value is 1-indexed.
-func match(file string, start int, lines []string, pattern string) (int, error) {
-	// $ matches the end of the file.
-	if pattern == "$" {
-		if len(lines) == 0 {
-			return 0, fmt.Errorf("%q: empty file", file)
-		}
-		return len(lines), nil
-	}
-	// /regexp/ matches the line that matches the regexp.
-	if len(pattern) > 2 && pattern[0] == '/' && pattern[len(pattern)-1] == '/' {
-		re, err := regexp.Compile(pattern[1 : len(pattern)-1])
-		if err != nil {
-			return 0, err
-		}
-		for i := start; i < len(lines); i++ {
-			if re.MatchString(lines[i]) {
-				return i + 1, nil
-			}
-		}
-		return 0, fmt.Errorf("%s: no match for %#q", file, pattern)
-	}
-	return 0, fmt.Errorf("unrecognized pattern: %q", pattern)
-}

present/code_test.go

@@ -55,7 +55,6 @@ func main() { // HLfunc
 		name       string
 		readFile   func(string) ([]byte, error)
 		sourceFile string
-		sourceLine int
 		cmd        string
 		err        string
 		Code