Bug fix for multi-line labels in CFG dot graph

After D154102 multi-line labels would get split incorrectly.
When CFG is generated for a function with basic block name longer
than 80 lines, then the header separator will be placed after the
line break for the label name instead of after the whole label name.
The fix is simple by just moving the insert of | character before the
line splitting happens.

Differential Revision: https://reviews.llvm.org/D159207

GitOrigin-RevId: ebf01690d9b3d922909d9aecdf1db1a944a56298
1 file changed