Merge commit 93a67259cf23 from llvm git (by ShengYi Hung):

[ToolChains][FreeBSD] Set default Linker to LLD for FreeBSD (#190596)

  When the linker is specified as ld, toolchain applies special handling
  by invoking (triple)-ld instead of resolving ld via standard PATH
  lookup. This causes GNU ld installed via the system package manager to
  take the precedence (since (triple)-ld appears earlier in the search
  path), effectively overriding ld.lld.

  As a result, we set the default Linker on FreeBSD to ld.lld to indicate
  we want to use lld by default.

PR:		292067
MFC after:	3 days

contrib/llvm-project/clang/lib/Driver/ToolChains/FreeBSD.h

@@ -91,6 +91,10 @@ class LLVM_LIBRARY_VISIBILITY FreeBSD : public Generic_ELF {
   // Until dtrace (via CTF) and LLDB can deal with distributed debug info,
   // FreeBSD defaults to standalone/full debug info.
   bool GetDefaultStandaloneDebug() const override { return true; }
+  // On FreeBSD, `/usr/bin/ld` is `ld.lld`, but other things may be installed in
+  // the path named `ld`  or `{triple}-ld`, which may be picked by preference if
+  // we default to `ld` here.
+  const char *getDefaultLinker() const override { return "ld.lld"; }
 
 protected:
   Tool *buildAssembler() const override;