Disable LTO on riscv64

Signed-off-by: David Abdurachmanov <davidlt@rivosinc.com>

mlir.spec

@@ -6,13 +6,17 @@
 %global mlir_version %{maj_ver}.%{min_ver}.%{patch_ver}
 %global mlir_srcdir mlir-%{mlir_version}%{?rc_ver:rc%{rc_ver}}.src
 
+%ifarch riscv64
+%global _lto_cflags %{nil}
+%endif
+
 # Opt out of https://fedoraproject.org/wiki/Changes/fno-omit-frame-pointer
 # https://bugzilla.redhat.com/show_bug.cgi?id=2158587
 %undefine _include_frame_pointers
 
 Name: mlir
 Version: %{mlir_version}%{?rc_ver:~rc%{rc_ver}}
-Release: 1%{?dist}
+Release: 1.0.riscv64%{?dist}
 Summary: Multi-Level Intermediate Representation Overview
 
 License: Apache-2.0 WITH LLVM-exception
@@ -200,6 +204,9 @@ export LD_LIBRARY_PATH=%{buildroot}/%{_libdir}
 %{_libdir}/cmake/mlir
 
 %changelog
+* Sun Jun 25 2023 David Abdurachmanov <davidlt@rivosinc.com> - 16.0.5-1.0.riscv64
+- Disable LTO on riscv64
+
 * Tue Jun 06 2023 Tulio Magno Quites Machado Filho <tuliom@redhat.com> - 16.0.5-1
 - Update to LLVM 16.0.5