tc_build: kernel: Use ld.lld as host linker when possible

Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: nathanchance

tc_build/kernel.py

@@ -44,6 +44,8 @@ def build(self):
         if self.can_use_clang_as_hostcc():
             if 'CC' in self.make_variables:
                 self.make_variables['HOSTCC'] = self.make_variables['CC']
+            if self.can_use_lld_as_hostld():
+                self.make_variables['HOSTLDFLAGS'] = '-fuse-ld=lld'
         else:
             self.make_variables['HOSTCC'] = 'gcc'
             self.make_variables['HOSTCXX'] = 'g++'
@@ -138,6 +140,9 @@ def get_toolchain_version(self):
     def can_use_clang_as_hostcc(self):
         return self._run_clang('-c')
 
+    def can_use_lld_as_hostld(self):
+        return self._run_clang('-fuse-lld')
+
     def needs_binutils(self):
         return not self.can_use_ias()