[RISCV] Fix wrong CFI directives
Summary: Removes CFI CFA directives that could incorrectly propagate
beyond the basic block they were inteded for. Specifically it removes
the epilogue CFI directives. See the branch_and_tail_call test for an
example of the issue. Should fix the stack unwinding issues caused by
the incorrect directives.
Reviewers: asb, lenary, shiva0217
Reviewed By: lenary
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69723
This is a prerequisite for building and linking hard- and soft-float
riscv worlds with clang and lld.
Requested by: jhb
MFC after: 1 week
X-MFC-With: r353358
96d5330da8