use DebugLoc default ctor instead of DebugLoc::getUnknownLoc()


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100214 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FloatingPointRegKill.cpp b/lib/Target/X86/X86FloatingPointRegKill.cpp
index 6a117dd..541083f 100644
--- a/lib/Target/X86/X86FloatingPointRegKill.cpp
+++ b/lib/Target/X86/X86FloatingPointRegKill.cpp
@@ -129,7 +129,7 @@
     }
     // Finally, if we found any FP code, emit the FP_REG_KILL instruction.
     if (ContainsFPCode) {
-      BuildMI(*MBB, MBBI->getFirstTerminator(), DebugLoc::getUnknownLoc(),
+      BuildMI(*MBB, MBBI->getFirstTerminator(), DebugLoc(),
               MF.getTarget().getInstrInfo()->get(X86::FP_REG_KILL));
       ++NumFPKill;
       Changed = true;