Poor error message from control flow at global scope

[davidstone]

Bugzilla Link	35114
Version	trunk
OS	Windows NT
CC	@hfinkel

Extended Description

If you compile the following code:

while(true) {}

You get the not especially helpful error message:

<source>:1:1: error: expected unqualified-id
while(true) {}
^
1 error generated.

This came up for me in the context of calling a macro that wrapped a few statements in a do { ... } while(false); construct, and I spend a fair amount of time looking for a missing semicolon somewhere before I finally found the problem. I would have preferred to get a message along the lines of "while loops not allowed outside of functions" or something else that directly says the problem from the user's perspective.

[inclyc]

work on this

[inclyc]

https://reviews.llvm.org/D129573