Add i686 -> i386 compiler-rt symlink

This ports the change from https://src.fedoraproject.org/rpms/compiler-rt/pull-request/67
to big-merge, which is a bit more complicated here due to the
explicit file lists.

By default compiler_rt_triple is the same as llvm_triple. For x86
it is i386-redhat-linux-gnu instead, with a symlink to the
llvm_triple i686-redhat-linux-gnu.

And then the file list also needs to ship that symlink.

Author: nikic

files.spec.inc

@@ -511,15 +511,20 @@
 %{_prefix}/lib/clang/%{maj_ver}/share/*.txt
 
 # Files that appear on all targets
-%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}/libclang_rt.*
+%{_prefix}/lib/clang/%{maj_ver}/lib/%{compiler_rt_triple}/libclang_rt.*
 
 %ifnarch s390x
-%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}/clang_rt.crtbegin.o
-%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}/clang_rt.crtend.o
+%{_prefix}/lib/clang/%{maj_ver}/lib/%{compiler_rt_triple}/clang_rt.crtbegin.o
+%{_prefix}/lib/clang/%{maj_ver}/lib/%{compiler_rt_triple}/clang_rt.crtend.o
 %endif
 
 %ifnarch %{ix86} s390x
-%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}/liborc_rt.a
+%{_prefix}/lib/clang/%{maj_ver}/lib/%{compiler_rt_triple}/liborc_rt.a
+%endif
+
+# Additional symlink if two triples are in use.
+%if "%{llvm_triple}" != "%{compiler_rt_triple}"
+%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}
 %endif
 
 %endif

install.spec.inc

@@ -202,10 +202,23 @@ echo "--gcc-triple=%{_target_cpu}-redhat-linux" >> %{buildroot}%{_sysconfdir}/%{
 
 %if %{without compat_build}
 
+# Triple where compiler-rt libs are installed. If it differs from llvm_triple, then there is
+# also a symlink llvm_triple -> compiler_rt_triple.
+%global compiler_rt_triple %{llvm_triple}
+
 %ifarch ppc64le
 # Fix install path on ppc64le so that the directory name matches the triple used
 # by clang.
-mv %{buildroot}%{_prefix}/lib/clang/%{maj_ver}/lib/powerpc64le-redhat-linux-gnu %{buildroot}%{_prefix}/lib/clang/%{maj_ver}/lib/ppc64le-redhat-linux-gnu
+mv %{buildroot}%{_prefix}/lib/clang/%{maj_ver}/lib/powerpc64le-redhat-linux-gnu %{buildroot}%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}
+%endif
+
+%ifarch %{ix86}
+# Fix install path on ix86 so that the directory name matches the triple used
+# by clang on both actual ix86 (i686) and on x86_64 with -m32 (i386):
+%global compiler_rt_triple i386-redhat-linux-gnu
+%if "%{llvm_triple}" != "%{compiler_rt_triple}"
+ln -s %{compiler_rt_triple} %{buildroot}%{_prefix}/lib/clang/%{maj_ver}/lib/%{llvm_triple}
+%endif
 %endif
 
 %endif