[ARM] Remove dead function ARMMCCodeEmitter::getSOImmOpValue

[sbc100]

Summary

The last reference to this function was removed from the ARM
td files in 2015 in rL225266.

[efriedma]

LGTM

llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp

public:
   unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
                            SmallVectorImpl<MCFixup> &Fixups,
                            const MCSubtargetInfo &STI) const {
     // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
     // '1' respectively.
     return MI.getOperand(Op).getReg() == ARM::CPSR;
   }
 
-  /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
-  unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
-                           SmallVectorImpl<MCFixup> &Fixups,
-                           const MCSubtargetInfo &STI) const {
-    const MCOperand &MO = MI.getOperand(Op);
-
-    // We expect MO to be an immediate or an expression,
-    // if it is an immediate - that's fine, just encode the value.
-    // Otherwise - create a Fixup.
-    if (MO.isExpr()) {
-      const MCExpr *Expr = MO.getExpr();
-      // In instruction code this value always encoded as lowest 12 bits,
-      // so we don't have to perform any specific adjustments.
-      // Due to requirements of relocatable records we have to use FK_Data_4.
-      // See ARMELFObjectWriter::ExplicitRelSym and
-      //     ARMELFObjectWriter::GetRelocTypeInner for more details.
-      MCFixupKind Kind = MCFixupKind(FK_Data_4);
-      Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
-      return 0;
-    }
-
-    unsigned SoImm = MO.getImm();
-    int SoImmVal = ARM_AM::getSOImmVal(SoImm);
-    assert(SoImmVal != -1 && "Not a valid so_imm value!");
-
-    // Encode rotate_imm.
-    unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
-      << ARMII::SoRotImmShift;
-
-    // Encode immed_8.
-    Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
-    return Binary;
-  }
-
   unsigned getModImmOpValue(const MCInst &MI, unsigned Op,
                             SmallVectorImpl<MCFixup> &Fixups,
                             const MCSubtargetInfo &ST) const {
     const MCOperand &MO = MI.getOperand(Op);
 
     // Support for fixups (MCFixup)
     if (MO.isExpr()) {
       const MCExpr *Expr = MO.getExpr();