[Sema] Fix crash in unused-lambda-capture warning for VLAs
Summary:
Clang was crashing when diagnosing an unused-lambda-capture for a VLA
because From.getVariable() is null for the capture of a VLA bound.
Warning about the VLA bound capture is not helpful, so only warn for
the VLA itself.
Fixes: PR35555
Reviewers: aaron.ballman, dim, rsmith
Reviewed By: aaron.ballman, dim
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D41016
This fixes a segfault when building recent audio/zynaddsubfx port
versions.
Reported by: hps
MFC after: 3 days
8c5bf9875d