Fix data formatters on Windows

[llvmbot]

Bugzilla Link	24462
Version	unspecified
OS	Windows NT
Blocks	#24834
Reporter	LLVM Bugzilla Contributor
CC	@stella.stamenova

Extended Description

Data formatters currently have a number of general issues preventing them from working on basic types in Windows.

Fixing these should allow re-enabling (at a minimum) the following tests:

TestDataFormatterCpp.py
TestDataFormatterDisabling.py
TestDataFormatterSkipSummary.py
TestDataFormatterSmartArray.py
TestDataFormatterSynthVal.py

There are other more specific issues related to STL data formatters (see Bug 24460) that should be addressed separately. But fixing these issues should be considered a pre-requisite to implementing STL data formatters.

[stella.stamenova]

Several of these tests are now passing. The current list of failing tests is:

TestDataFormatterDisabling.py
TestDataFormatterSkipSummary.py
TestDataFormatterSynthVal.py

[DavidSpickett]

The last test was fixed, these two are still xfailed for Windows:
TestDataFormatterDisabling.py
TestDataFormatterSkipSummary.py

[DavidSpickett]

Both of the above are now passing on Windows.