Reuse isWhitespace and isNewline, also refactoring readAtFile

src/util.cpp

@@ -5,6 +5,14 @@
 #include <stdint.h>
 #include <stdio.h>
 
+bool isWhitespace(int c) {
+	return c == ' ' || c == '\t';
+}
+
+bool isNewline(int c) {
+	return c == '\r' || c == '\n';
+}
+
 bool startsIdentifier(int c) {
 	// This returns false for anonymous labels, which internally start with a '!',
 	// and for section fragment literal labels, which internally start with a '$'.
@@ -25,7 +33,8 @@ char const *printChar(int c) {
 		return "EOF";
 	}
 
-	if (isprint(c)) {
+	// Handle printable ASCII characters
+	if (c >= ' ' && c <= '~') {
 		buf[0] = '\'';
 		buf[1] = c;
 		buf[2] = '\'';