toolchain/54258: pull llvm's upstream change to revert workarounds on sparc64

[nakayama%NetBSD.org@localhost]

>Number:         54258
>Category:       toolchain
>Synopsis:       pull llvm's upstream change to revert workarounds on sparc64
>Confidential:   no
>Severity:       non-critical
>Priority:       high
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jun 01 06:45:00 +0000 2019
>Originator:     Takeshi Nakayama
>Release:        NetBSD-current
>Organization:
>Environment:
>Description:
Joerg fixed upstream clang since the cause was determined by the
following commits for workaround on sparc64.

http://mail-index.netbsd.org/source-changes/2019/04/05/msg104803.html
http://mail-index.netbsd.org/source-changes/2019/04/05/msg104782.html
http://mail-index.netbsd.org/source-changes/2019/04/05/msg104783.html
http://mail-index.netbsd.org/source-changes/2019/04/06/msg104840.html

>How-To-Repeat:
	
>Fix:
pull upstream change:

https://llvm.org/viewvc/llvm-project?view=revision&revision=358998
https://github.com/llvm/llvm-project/commit/6e7cc49d5cb31ee09b07252b6641d7c94977fd12