Enable PIC even for static libraries

Start using CMAKE_POSITION_INDEPENDENT_CODE=ON in order to keep the same
behavior that existed before a set of changes modified it and ended up
with the inclusion of CMAKE_POSITION_INDEPENDENT_CODE in commit
a6e5563dfaff0cb7147058b9c49e38b611a28fb1.

Fixes: rhbz#2186531

llvm-libunwind.spec

@@ -9,7 +9,7 @@
 
 Name:       llvm-libunwind
 Version:    %{libunwind_version}%{?rc_ver:~rc%{rc_ver}}
-Release:    1%{?dist}
+Release:    2%{?dist}
 Summary:    LLVM libunwind
 
 License:    ASL 2.0 or NCSA or MIT
@@ -77,6 +77,7 @@ export ASMFLAGS=$CFLAGS
 %cmake -GNinja \
     -DCMAKE_MODULE_PATH=%{_libdir}/cmake/llvm \
     -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+    -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
     -DLLVM_BUILD_DOCS=ON \
     -DLLVM_ENABLE_SPHINX=ON \
     -DLIBUNWIND_INCLUDE_DOCS=ON \
@@ -137,6 +138,9 @@ rm %{buildroot}%{_pkgdocdir}/html/.buildinfo
 %doc %{_pkgdocdir}/html
 
 %changelog
+* Wed May 03 2023 Tulio Magno Quites Machado Filho <tuliom@redhat.com> - 15.0.7-2
+- Enable PIC even for static libraries (rhbz#2186531)
+
 * Fri Jan 13 2023 Nikita Popov <npopov@redhat.com> - 15.0.7-1
 - Update to LLVM 15.0.7