[llvm-readobj/llvm-readelf] Delete --arm-attributes (alias for --arch-specific)

[MaskRay]

Summary

D68110 added --arch-specific (supported by GNU readelf) and made
--arm-attributes an alias for it. The tests were later migrated to use
--arch-specific.

Note, llvm-readelf --arch-specific currently just uses llvm-readobj
style output for ARM attributes. The readelf-style output is not
implemented.

[compnerd]

Thanks for cleaning this up

docs/CommandGuide/llvm-readelf.rst

 .. option:: --all
 
  Equivalent to specifying all the main display options.
 
 .. option:: --addrsig
 
  Display the address-significance table.
 
-.. option:: --arm-attributes
+.. option:: --arch-specific, -A
 
- Display the ARM attributes section. Only applicable for ARM architectures.
+ Display architecture-specific information, e.g. the ARM attributes section on ARM.
 
 .. option:: --color
 
  Use colors in the output for warnings and errors.
 
 .. option:: --demangle, -C
 
  Display demangled symbol names in the output.

docs/CommandGuide/llvm-readobj.rst

 
  Read command-line options from response file `<FILE>`.
 
 ELF SPECIFIC OPTIONS
 --------------------
 
 The following options are implemented only for the ELF file format.
 
-.. option:: --arm-attributes
+.. option:: --arch-specific, -A
 
- Display the ARM attributes section. Only applicable for ARM architectures.
+ Display architecture-specific information, e.g. the ARM attributes section on ARM.
 
 .. option:: --demangle, -C
 
  Display demangled symbol names in the output.
 
 .. option:: --dyn-relocations
 
  Display the dynamic relocation entries.

test/tools/llvm-readobj/ARM/attribute-conformance-1.s

 @ RUN: llvm-mc -triple armv7-elf -filetype asm -o - %s | FileCheck %s
 @ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
 @ RUN:   | llvm-readobj --arch-specific - | FileCheck %s --check-prefix=CHECK-OBJ
 @ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
 @ RUN:   | llvm-readobj -A - | FileCheck %s --check-prefix=CHECK-OBJ
-@ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
-@ RUN:   | llvm-readobj --arm-attributes - | FileCheck %s --check-prefix=CHECK-OBJ
 .eabi_attribute  Tag_conformance, "0"
 @CHECK:   .eabi_attribute 67, "0"
 @CHECK-OBJ: Tag: 67
 @CHECK-OBJ-NEXT: TagName: conformance
 @CHECK-OBJ-NEXT: Value: 0

test/tools/llvm-readobj/ARM/attribute-conformance-2.s

 @ RUN: llvm-mc -triple armv7-elf -filetype asm -o - %s | FileCheck %s
 @ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
 @ RUN:   | llvm-readobj --arch-specific - | FileCheck %s --check-prefix=CHECK-OBJ
 @ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
 @ RUN:   | llvm-readobj -A - | FileCheck %s --check-prefix=CHECK-OBJ
-@ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
-@ RUN:   | llvm-readobj --arm-attributes - | FileCheck %s --check-prefix=CHECK-OBJ
 .eabi_attribute  Tag_conformance, "A.long--non numeric oddity...!!"
 @CHECK:   .eabi_attribute 67, "A.long--non numeric oddity...!!"
 @CHECK-OBJ: Tag: 67
 @CHECK-OBJ-NEXT: TagName: conformance
 @CHECK-OBJ-NEXT: Value: A.long--non numeric oddity...!!

tools/llvm-readobj/llvm-readobj.cpp

cl::opt<bool> CodeViewSubsectionBytes(
       "codeview-subsection-bytes",
       cl::desc("Dump raw contents of codeview debug sections and records"));
 
   // --arch-specific
   cl::opt<bool> ArchSpecificInfo("arch-specific",
                               cl::desc("Displays architecture-specific information, if there is any."));
   cl::alias ArchSpecifcInfoShort("A", cl::desc("Alias for --arch-specific"),
                                  cl::aliasopt(ArchSpecificInfo), cl::NotHidden);
-  cl::alias ARMAttributes("arm-attributes", cl::desc("Alias for --arch-specific"),
-                           cl::aliasopt(ArchSpecificInfo), cl::Hidden);
 
   // --mips-plt-got
   cl::opt<bool>
   MipsPLTGOT("mips-plt-got",
              cl::desc("Display the MIPS GOT and PLT GOT sections"));
 
   // --mips-abi-flags
   cl::opt<bool> MipsABIFlags("mips-abi-flags",