Java: Split literals tests

This allows changing individual tests in the future without having to adjust
the expected output of all other tests.

java/ql/test/library-tests/literals/integerLiterals/IntegerLiterals.java

@@ -0,0 +1,57 @@
+package integerLiterals;
+
+public class IntegerLiterals {
+	int[] ints = {
+		0,
+		1,
+		0_0,
+		0___0,
+		0_12, // octal
+		0X012, // hex
+		0xaBcDeF, // hex
+		0B11, // binary
+		0x80000000,
+		2147483647,
+		-2147483648, // special case: sign is part of the literal
+		// From the JLS
+		0x7fff_ffff,
+		0177_7777_7777, // octal
+		0b0111_1111_1111_1111_1111_1111_1111_1111, // binary
+		0x8000_0000,
+		0200_0000_0000,
+		0b1000_0000_0000_0000_0000_0000_0000_0000,
+		0xffff_ffff,
+		0377_7777_7777,
+		0b1111_1111_1111_1111_1111_1111_1111_1111,
+		// Using Unicode escapes (which are handled during pre-processing)
+		\u0030, // 0
+	};
+
+	// + and - are not part of the literal
+	int[] intsWithSign = {
+		+0,
+		-0,
+		+1,
+		-1,
+		+2147483647,
+	};
+
+	// The operation expression (e.g. `+`) is not a literal
+	int[] numericOperations = {
+		1 + 1,
+		0 / 0,
+	};
+
+	Object[] nonIntLiterals = {
+		"0",
+		'0',
+		0L,
+		(int) 0L,
+		0.0,
+		(int) 0.0,
+		Integer.MIN_VALUE,
+		'a' + 'b', // result is int 195, but this is not a literal
+	};
+
+	int nonLiteral;
+}