Backport upstream patch to fix build with -flto.

Also disable LTO on s390x to work-around unit test failures.

0001-llvm-Avoid-linking-llvm-cfi-verify-to-duplicate-libs.patch

@@ -0,0 +1,50 @@
+From 352558e69b3691cfdc8e1adc2a1fbb737bc67cbb Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
+Date: Tue, 16 Jun 2020 12:16:52 +0200
+Subject: [PATCH] [llvm] Avoid linking llvm-cfi-verify to duplicate libs
+
+Fix the CMake rules for LLVMCFIVerify library not to pull duplicate
+LLVM .a libraries when linking to the dylib.  This prevents problems
+due to duplicate symbols and apparently fixes mingw32.
+
+This is an alternative approach to D44650 that just forces .a libraries
+instead.  However, there doesn't seem to be any reason to do that.
+
+Differential Revision: https://reviews.llvm.org/D81921
+---
+ llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt | 20 +++++++++++--------
+ 1 file changed, 12 insertions(+), 8 deletions(-)
+
+diff --git a/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt b/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt
+index 82ca42e624a..41d55ed9321 100644
+--- a/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt
++++ b/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt
+@@ -7,13 +7,17 @@ add_library(LLVMCFIVerify
+   )
+ 
+ llvm_update_compile_flags(LLVMCFIVerify)
+-llvm_map_components_to_libnames(libs
+-  DebugInfoDWARF
+-  MC
+-  MCParser
+-  Object
+-  Support
+-  Symbolize
+-  )
++if (LLVM_LINK_LLVM_DYLIB)
++  set(libs LLVM)
++else()
++  llvm_map_components_to_libnames(libs
++    DebugInfoDWARF
++    MC
++    MCParser
++    Object
++    Support
++    Symbolize
++    )
++endif()
+ target_link_libraries(LLVMCFIVerify ${libs})
+ set_target_properties(LLVMCFIVerify PROPERTIES FOLDER "Libraries")
+-- 
+2.18.1
+

llvm.spec

@@ -11,7 +11,7 @@
 %global llvm_libdir %{_libdir}/%{name}
 %global build_llvm_libdir %{buildroot}%{llvm_libdir}
 #%%global rc_ver 6
-%global baserelease 9
+%global baserelease 10
 %global llvm_srcdir llvm-%{version}%{?rc_ver:rc%{rc_ver}}.src
 %global maj_ver 10
 %global min_ver 0
@@ -62,6 +62,7 @@ Patch0:		0001-CMake-Split-static-library-exports-into-their-own-ex.patch
 Patch1:		0001-CMake-Split-test-binary-exports-into-their-own-expor.patch
 %endif
 Patch2:		bab5908df544680ada0a3cf431f55aeccfbdb321.patch
+Patch3:		0001-llvm-Avoid-linking-llvm-cfi-verify-to-duplicate-libs.patch
 
 BuildRequires:	gcc
 BuildRequires:	gcc-c++
@@ -175,6 +176,15 @@ pathfix.py -i %{__python3} -pn \
 
 %build
 
+# Disable LTO on s390x, this causes some test failures:
+# LLVM-Unit :: Target/AArch64/./AArch64Tests/InstSizes.Authenticated
+# LLVM-Unit :: Target/AArch64/./AArch64Tests/InstSizes.PATCHPOINT
+# LLVM-Unit :: Target/AArch64/./AArch64Tests/InstSizes.STACKMAP
+# LLVM-Unit :: Target/AArch64/./AArch64Tests/InstSizes.TLSDESC_CALLSEQ
+%ifarch s390x
+%global _lto_cflags %{nil}
+%endif
+
 %ifarch s390 %{arm} %ix86
 # Decrease debuginfo verbosity to reduce memory consumption during final library linking
 %global optflags %(echo %{optflags} | sed 's/-g /-g1 /')
@@ -517,6 +527,10 @@ fi
 %endif
 
 %changelog
+* Tue Aug 04 2020 Tom Stellard <tstellar@redhat.com> - 10.0.0-10
+- Backport upstream patch to fix build with -flto.
+- Disable LTO on s390x to work-around unit test failures.
+
 * Sat Aug 01 2020 sguelton@redhat.com - 10.0.0-9
 - Fix update-alternative uninstall script