ARMv5TE (DS) support (#68)

* 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

---------

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

objdiff-core/Cargo.toml

@@ -12,13 +12,14 @@ A local diffing tool for decompilation projects.
 """
 
 [features]
-all = ["config", "dwarf", "mips", "ppc", "x86"]
+all = ["config", "dwarf", "mips", "ppc", "x86", "arm"]
 any-arch = [] # Implicit, used to check if any arch is enabled
 config = ["globset", "semver", "serde_json", "serde_yaml"]
 dwarf = ["gimli"]
 mips = ["any-arch", "rabbitizer"]
 ppc = ["any-arch", "cwdemangle", "ppc750cl"]
 x86 = ["any-arch", "cpp_demangle", "iced-x86", "msvc-demangler"]
+arm = ["any-arch", "cpp_demangle", "unarm"]
 
 [dependencies]
 anyhow = "1.0.82"
@@ -53,3 +54,6 @@ rabbitizer = { version = "1.11.0", optional = true }
 cpp_demangle = { version = "0.4.3", optional = true }
 iced-x86 = { version = "1.21.0", default-features = false, features = ["std", "decoder", "intel", "gas", "masm", "nasm", "exhaustive_enums"], optional = true }
 msvc-demangler = { version = "0.10.0", optional = true }
+
+# arm
+unarm = { version = "1.0.0", optional = true }