ARMv4T (GBA) and ARMv6K (3DS) support (#75)

* Initial ARM support

* Disassemble const pool reloc

* Disasm ARM/Thumb/data based on mapping symbols

* Fallback to mapping symbol `$a`

* Support multiple DWARF sequences

* Update line info

* Rework DWARF line info parsing

- Properly handles multiple sections
  in DWARF 1
- line_info moved into ObjSection
- DWARF 2 parser no longer errors with
  no .text section
- Both parsers properly skip empty
  sections

* Simplify line_info (no Option)

* Get line info from section; output formatted ins string

* Unwrap code section in `arm.rs`

* Handle reloc `R_ARM_SBREL32`

* Update ARM disassembler

* Update README.md

* Format

* Revert "Update README.md"

This reverts commit 8bbfcc6f45.

* Update README.md

* Detect ARM version; support ARMv4T and v6K

* Combobox to force ARM version

* Clear LSB in ARM symbol addresses

* Support big-endian ARM ELF files

* Bump `unarm`, `arm-attr`

* Handle ARM implicit addends

* Update README.md

* Explicitly handle all ARM argument types

* Format

* Display more ARM relocs

* Mask LSB on ARM code symbols only

* Read ARM implicit addends

* Format

---------

Co-authored-by: Luke Street <luke.street@encounterpc.com>

objdiff-gui/src/views/config.rs

@@ -16,7 +16,7 @@ use egui::{
 use globset::Glob;
 use objdiff_core::{
     config::{ProjectObject, DEFAULT_WATCH_PATTERNS},
-    diff::{MipsAbi, MipsInstrCategory, X86Formatter},
+    diff::{ArmArchVersion, MipsAbi, MipsInstrCategory, X86Formatter},
 };
 use self_update::cargo_crate_version;
 use strum::{EnumMessage, VariantArray};
@@ -907,4 +907,22 @@ fn arch_config_ui(ui: &mut egui::Ui, config: &mut AppConfig, _appearance: &Appea
                 }
             }
         });
+    ui.separator();
+    ui.heading("ARM");
+    egui::ComboBox::new("arm_arch_version", "Architecture Version")
+        .selected_text(config.diff_obj_config.arm_arch_version.get_message().unwrap())
+        .show_ui(ui, |ui| {
+            for &version in ArmArchVersion::VARIANTS {
+                if ui
+                    .selectable_label(
+                        config.diff_obj_config.arm_arch_version == version,
+                        version.get_message().unwrap(),
+                    )
+                    .clicked()
+                {
+                    config.diff_obj_config.arm_arch_version = version;
+                    config.queue_reload = true;
+                }
+            }
+        });
 }