[WebAssembly] Remove ELF file support.

This support was partial and temporary.  Now that we have
wasm object file support its no longer needed.

Differential Revision: https://reviews.llvm.org/D48744

llvm-svn: 337222
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
index dc51d7a..9f5d5bd 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
@@ -749,14 +749,6 @@
   MachineDominatorTree &MDT = getAnalysis<MachineDominatorTree>();
   LiveIntervals &LIS = getAnalysis<LiveIntervals>();
 
-  // Disable the TEE optimization if we aren't doing direct wasm object
-  // emission, because lowering TEE to TEE_LOCAL is done in the ExplicitLocals
-  // pass, which is also disabled.
-  bool UseTee = true;
-  if (MF.getSubtarget<WebAssemblySubtarget>()
-        .getTargetTriple().isOSBinFormatELF())
-    UseTee = false;
-
   // Walk the instructions from the bottom up. Currently we don't look past
   // block boundaries, and the blocks aren't ordered so the block visitation
   // order isn't significant, but we may want to change this in the future.
@@ -822,7 +814,7 @@
           Insert =
               RematerializeCheapDef(Reg, Op, *Def, MBB, Insert->getIterator(),
                                     LIS, MFI, MRI, TII, TRI);
-        } else if (UseTee && CanMove &&
+        } else if (CanMove &&
                    OneUseDominatesOtherUses(Reg, Op, MBB, MRI, MDT, LIS, MFI)) {
           Insert = MoveAndTeeForMultiUse(Reg, Op, Def, MBB, Insert, LIS, MFI,
                                          MRI, TII);