LibJS: Support all line terminators (LF, CR, LS, PS)

https://tc39.es/ecma262/#sec-line-terminators

Libraries/LibJS/Tests/parser-line-terminators.js

@@ -0,0 +1,53 @@
+/*
+These tests deliberately produce syntax errors to check what line the parser thinks we're on.
+
+⚠ PLEASE MAKE SURE TO NOT LET YOUR EDITOR REMOVE THE LS/PS LINE TERMINATORS!
+*/
+
+test("LINE FEED is a line terminator", () => {
+    expect(() => {
+        Function("\n\n@");
+    }).toThrowWithMessage(SyntaxError, "line: 3, column: 1");
+});
+
+test("CARRIAGE RETURN is a line terminator", () => {
+    expect(() => {
+        Function("\r\r@");
+    }).toThrowWithMessage(SyntaxError, "line: 3, column: 1");
+});
+
+test("LINE SEPARATOR is a line terminator", () => {
+    expect(() => {
+        Function(`

@`);
+    }).toThrowWithMessage(SyntaxError, "line: 3, column: 1");
+});
+
+test("PARAGRAPH SEPARATOR is a line terminator", () => {
+    expect(() => {
+        Function(`

@`);
+    }).toThrowWithMessage(SyntaxError, "line: 3, column: 1");
+});
+
+test("CR LF is counted as only one line terminator", () => {
+    expect(() => {
+        Function("\r\n\r\n@");
+    }).toThrowWithMessage(SyntaxError, "line: 3, column: 1");
+});
+
+test("LF/CR are not allowed in string literal", () => {
+    expect(() => {
+        Function(`"
+        "`);
+    }).toThrowWithMessage(SyntaxError, "Unexpected token UnterminatedStringLiteral");
+});
+
+test("LS/PS are allowed in string literal", () => {
+    expect(`"
"`).toEval();
+    expect(`"
"`).toEval();
+});
+
+test("line terminators can be mixed (but please don't)", () => {
+    expect(() => {
+        Function(`\r\
\r\n
\n\r@`);
+    }).toThrowWithMessage(SyntaxError, "line: 7, column: 1");
+});