[llvm] [LFI][X86] Add control-flow rewrites (PR #210913)

[Zachary Yedidia via llvm-commits]

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@@ -35,6 +36,37 @@ static bool isSyscall(const MCInst &Inst) {
   return Inst.getOpcode() == X86::SYSCALL;
 }
 
+static bool isDirectCall(const MCInst &Inst) {
+  switch (Inst.getOpcode()) {
+  case X86::CALLpcrel32:
+  case X86::CALL64pcrel32:
+    return true;
+  default:
+    return false;
+  }
+}
+
+static bool isSupportedIndirectBranch(const MCInst &Inst) {
+  switch (Inst.getOpcode()) {
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zyedidia wrote:

TAILJMP* opcodes are codegen-only pseudo-instructions that X86MCInstLower converts to MCInst x86-64 opcodes before the instruction reaches the streamer, so we don't need to handle them.

https://github.com/llvm/llvm-project/pull/210913