Update code to silent some ARM/ARM64 specific compiler warnings

[omjavaid]

Summary

Following changes remove conditions where an unsigned integer is being tested to be greater or equal to zero.

These conditions will always remain true and will result in compiler warning though most compilers will optimize this out.

[tberghammer]

We discussed the same change recently (D13866) and the general opinion was that the original code have the right semantics and we don't want to change it just to silence some warnings.

If you want to get rid of these warnings then I would suggest to do it with adding a cast before the comparison (I haven't tested it):

if ((int)reg_num >= x0 && (int)reg_num <= pc) // We are casting to int to silence a gcc warning

[omjavaid]

Let the warnings stay for now.

source/Plugins/Instruction/ARM/EmulationStateARM.cpp

EmulationStateARM::LoadPseudoRegistersFromFrame (StackFrame &frame)
     }
     
     return success;
 }
     
 bool
 EmulationStateARM::StorePseudoRegisterValue (uint32_t reg_num, uint64_t value)
 {
-    if ((dwarf_r0 <= reg_num) && (reg_num <= dwarf_cpsr))
+    if (reg_num <= dwarf_cpsr)
         m_gpr[reg_num  - dwarf_r0] = (uint32_t) value;
     else if ((dwarf_s0 <= reg_num) && (reg_num <= dwarf_s31))
     {
         uint32_t idx = reg_num - dwarf_s0;
         m_vfp_regs.sd_regs[idx / 2].s_reg[idx % 2] = (uint32_t) value;
     }
     else if ((dwarf_d0 <= reg_num) && (reg_num <= dwarf_d31))
     {

 }
     
 uint64_t
 EmulationStateARM::ReadPseudoRegisterValue (uint32_t reg_num, bool &success)
 {
     uint64_t value = 0;
     success = true;
     
-    if ((dwarf_r0 <= reg_num) && (reg_num <= dwarf_cpsr))
+    if (reg_num <= dwarf_cpsr)
         value = m_gpr[reg_num  - dwarf_r0];
     else if ((dwarf_s0 <= reg_num) && (reg_num <= dwarf_s31))
     {
         uint32_t idx = reg_num - dwarf_s0;
         value = m_vfp_regs.sd_regs[idx / 2].s_reg[idx % 2];
     }
     else if ((dwarf_d0 <= reg_num) && (reg_num <= dwarf_d31))
     {

source/Utility/ARM64_DWARF_Registers.cpp

 }
 
 bool
 arm64_dwarf::GetRegisterInfo (unsigned reg_num, RegisterInfo &reg_info)
 {
     ::memset (&reg_info, 0, sizeof(RegisterInfo));
     ::memset (reg_info.kinds, LLDB_INVALID_REGNUM, sizeof(reg_info.kinds));
     
-    if (reg_num >= x0 && reg_num <= pc)
+    if (reg_num <= pc)
     {
         reg_info.byte_size = 8;
         reg_info.format = eFormatHex;
         reg_info.encoding = eEncodingUint;
     }
     else if (reg_num >= v0 && reg_num <= v31)
     {
         reg_info.byte_size = 16;