feat: add bitwise XOR, left shift, and right shift operators to Wren language

Add three new bitwise operators (^, <<, >>) to the Wren compiler and runtime,
including tokenization, parsing with correct precedence, and native method
implementations operating on 32-bit unsigned integers. New test files verify
correct behavior for edge cases including max u32 values and operand type errors.

test/number/bitwise_lsh.wren

@@ -0,0 +1,15 @@
+IO.print(0 << 0) // expect: 0
+IO.print(1 << 0) // expect: 1
+IO.print(0 << 1) // expect: 0
+IO.print(1 << 1) // expect: 2
+IO.print(2863311530 << 1) // expect: 1431655764
+IO.print(4042322160 << 1) // expect: 3789677024
+
+// Max u32 value.
+IO.print(4294967295 << 1) // expect: 4294967294
+
+// Past max u32 value.
+IO.print(4294967296 << 1) // expect: 0
+
+// TODO: Negative numbers.
+// TODO: Floating-point numbers.

test/number/bitwise_lsh_operand_not_num.wren

@@ -0,0 +1 @@
+1 << false // expect runtime error: Right operand must be a number.

test/number/bitwise_rsh.wren

@@ -0,0 +1,15 @@
+IO.print(0 >> 0) // expect: 0
+IO.print(1 >> 0) // expect: 1
+IO.print(0 >> 1) // expect: 0
+IO.print(1 >> 1) // expect: 0
+IO.print(2863311530 >> 1) // expect: 1431655765
+IO.print(4042322160 >> 1) // expect: 2021161080
+
+// Max u32 value.
+IO.print(4294967295 >> 1) // expect: 2147483647
+
+// Past max u32 value.
+IO.print(4294967296 >> 1) // expect: 0
+
+// TODO: Negative numbers.
+// TODO: Floating-point numbers.

test/number/bitwise_rsh_operand_not_num.wren

@@ -0,0 +1 @@
+1 >> false // expect runtime error: Right operand must be a number.

test/number/bitwise_xor.wren

@@ -0,0 +1,15 @@
+IO.print(0 ^ 0) // expect: 0
+IO.print(1 ^ 1) // expect: 0
+IO.print(0 ^ 1) // expect: 1
+IO.print(1 ^ 0) // expect: 1
+IO.print(2863311530 ^ 1431655765) // expect: 4294967295
+IO.print(4042322160 ^ 1010580540) // expect: 3435973836
+
+// Max u32 value.
+IO.print(4294967295 ^ 4294967295) // expect: 0
+
+// Past max u32 value.
+IO.print(4294967296 ^ 4294967296) // expect: 0
+
+// TODO: Negative numbers.
+// TODO: Floating-point numbers.

test/number/bitwise_xor_operand_not_num.wren

@@ -0,0 +1 @@
+1 ^ false // expect runtime error: Right operand must be a number.