ArchSpec: fix unintentional promotion of unspecified unknowns to specified unknowns

* ArchSpec::MergeFrom() would erroneously promote an unspecified
  unknown to a specified unknown when both the ArchSpec and the merged
  in ArchSpec were both unspecified unknowns. This no longer happens,
  which fixes issues with global module cache lookup in some
  situations.

* Added ArchSpec::DumpTriple(Stream&) that now properly prints
  unspecified unknowns as '*' and specified unknows as 'unknown'.
  This makes it trivial to tell the difference between the two.
  Converted printing code over ot using DumpTriple() rather than
  building from scratch.

* Fixed up a couple places that were not guaranteeing that an
  unspecified unknown was recorded as such.

llvm-svn: 250253

1 files changed, 2 insertions, 2 deletions

diff --git a/lldb/source/Host/linux/HostInfoLinux.cpp b/lldb/source/Host/linux/HostInfoLinux.cpp
index 3a3023b1343..4732a2a571b 100644
--- a/lldb/source/Host/linux/HostInfoLinux.cpp
+++ b/lldb/source/Host/linux/HostInfoLinux.cpp
@@ -271,12 +271,12 @@ HostInfoLinux::ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arch_
     {
         arch_32.SetDistributionId(distribution_id);
         if (arch_32.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
-            arch_32.GetTriple().setVendorName("");
+            arch_32.GetTriple().setVendorName(llvm::StringRef());
     }
     if (arch_64.IsValid())
     {
         arch_64.SetDistributionId(distribution_id);
         if (arch_64.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
-            arch_64.GetTriple().setVendorName("");
+            arch_64.GetTriple().setVendorName(llvm::StringRef());
     }
 }