Fix TestSBData.py on Windows (which uses Python 3)

[amccarth]

Summary

This test uses the SB API to set and read back bytes of data, and it works fine when Python 2 is the scripting language. On Windows, however, Python 3 is the default.

Note this line from the test:

addr_data = '\x11\x22\x33\x44\x55\x66\x77\x88'

The intent here is to create an array of eight bytes as a string literal. This works in Python 2, but Python 3 treats those as a series Unicode code points, and the CPython implementation happens to encode those code points as UTF-8. The first seven characters encode directly as single bytes of the same value. But the UTF-8 encoding of 0x88 is two bytes long: 0xC2 0x88. So the input array doesn't have the intended data at the end, so the test cases that use all eight bytes fail.

Adding the b prefix tells Python 3 that we want a byte array rather than a string. With this change, the test now passes on Windows. I believe this also works for Python 2 (Python 2.7 accepts the b-prefix and seems to do the right thing), but I'm not very familiar with the details of Python 2.

lldb/packages/Python/lldbsuite/test/python_api/sbdata/TestSBData.py

def setUp(self):
         TestBase.setUp(self)
         # Find the line number to break on inside main.cpp.
         self.line = line_number('main.cpp', '// set breakpoint here')
 
     @add_test_categories(['pyapi'])
     def test_byte_order_and_address_byte_size(self):
         """Test the SBData::SetData() to ensure the byte order and address 
         byte size are obeyed"""
-        addr_data = '\x11\x22\x33\x44\x55\x66\x77\x88'
+        addr_data = b'\x11\x22\x33\x44\x55\x66\x77\x88'
         error = lldb.SBError()
         data = lldb.SBData()
         data.SetData(error, addr_data, lldb.eByteOrderBig, 4)
         addr = data.GetAddress(error, 0)
         self.assertTrue(addr == 0x11223344);
         data.SetData(error, addr_data, lldb.eByteOrderBig, 8)
         addr = data.GetAddress(error, 0)
         self.assertTrue(addr == 0x1122334455667788);