Re-apply: Warning for framework headers using double quote includes
Introduce -Wquoted-include-in-framework-header, which should fire a warning
whenever a quote include appears in a framework header and suggest a fix-it.
For instance, for header A.h added in the tests, this is how the warning looks
./A.framework/Headers/A.h:2:10: warning: double-quoted include "A0.h" in framework header, expected angle-bracketed instead [-Wquoted-include-in-framework-header]
./A.framework/Headers/A.h:3:10: warning: double-quoted include "B.h" in framework header, expected angle-bracketed instead [-Wquoted-include-in-framework-header]
This helps users to prevent frameworks from using local headers when in fact
they should be targetting system level ones.
The warning is off by default.
Differential Revision: https://reviews.llvm.org/D47157