Revert "r225808 - [PowerPC] Add StackMap/PatchPoint support"

Reverting this while I investiage buildbot failures (segfaulting in
GetCostForDef at ScheduleDAGRRList.cpp:314).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225811 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/PowerPC/ppc64-stackmap-nops.ll

@@ -1,24 +0,0 @@
-; RUN: llc < %s -mtriple=powerpc64-unknown-gnu-linux | FileCheck %s
-
-define void @test_shadow_optimization() {
-entry:
-; Expect 12 bytes worth of nops here rather than 32: With the shadow optimization
-; in place, 20 bytes will be consumed by the frame teardown and return instr.
-; CHECK-LABEL: test_shadow_optimization:
-
-; CHECK:      nop
-; CHECK-NEXT: nop
-; CHECK-NEXT: nop
-; CHECK-NOT:  nop
-; CHECK: addi 1, 1, 64
-; CHECK: ld [[REG1:[0-9]+]], 16(1)
-; CHECK: ld 31, -8(1)
-; CHECK: mtlr [[REG1]]
-; CHECK: blr
-
-  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64  0, i32  32)
-  ret void
-}
-
-declare void @llvm.experimental.stackmap(i64, i32, ...)
-