[COMMITTED] Add glibc-ubuntu-riscv builder

[Mark Wielaard <mark@klomp.org>]

The glibc build takes a long time ~30 minutes for make -j4
and ~2.5 hours for make check -j4. But the result is pretty good:

                === Summary of results ===
      4 FAIL
   4698 PASS
     21 UNSUPPORTED
     16 XFAIL
      2 XPASS

Since it takes such a long time glibc builds for riscv are done
one one specific board and the builds are collapsed (we won't try
a build for every single commit).
---
 builder/master.cfg | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/builder/master.cfg b/builder/master.cfg
index 5f21a2b..84b7b3d 100644
--- a/builder/master.cfg
+++ b/builder/master.cfg
@@ -1040,6 +1040,7 @@ glibc_build_scheduler = schedulers.AnyBranchScheduler(
                       "glibc-fedora-s390x",
                       "glibc-debian-ppc64",
                       "glibc-fedora-ppc64le",
+                      "glibc-ubuntu-riscv",
                       "glibc-gentoo-sparc"])
 c['schedulers'].append(glibc_build_scheduler)
 
@@ -3861,6 +3862,14 @@ glibc_fedora_ppc64le_builder = util.BuilderConfig(
         factory=glibc_build_factory)
 c['builders'].append(glibc_fedora_ppc64le_builder)
 
+glibc_ubuntu_riscv_builder = util.BuilderConfig(
+        name="glibc-ubuntu-riscv",
+        collapseRequests=True,
+        workernames=["starfive-riscv"], # note only uses one specific starfive
+        tags=["glibc", "ubuntu", "riscv"],
+        factory=glibc_factory)
+c['builders'].append(glibc_ubuntu_riscv_builder)
+
 glibc_gentoo_sparc_builder = util.BuilderConfig(
         name="glibc-gentoo-sparc",
         collapseRequests=True,
-- 
2.39.3