Visualization for str is broken in the latest Windows SDK

[wesleywiser]

The update to the latest version of the Windows SDK broke the str visualization.

Related to #88796

[michaelwoerister]

This is very mysterious. It works just fine in other tests like here:

rust/src/test/debuginfo/pretty-std.rs

Lines 88 to 89 in 31d754a

	// cdb-command: dx str_slice
	// cdb-check:str_slice : "IAMA string slice!" [Type: str]

But it still reproduces with a current 1.66 nightly.