[llvm] ELFRelocs/AArch64: update canonical reference URL (NFC) (PR #86955)

[Peter Smith via llvm-commits]

================
@@ -1,18 +1,19 @@
-
 #ifndef ELF_RELOC
 #error "ELF_RELOC must be defined"
 #endif
 
-// Based on ABI release 1.1-beta, dated 6 November 2013. NB: The cover page of
-// this document, IHI0056C_beta_aaelf64.pdf, on infocenter.arm.com, still
-// labels this as release 1.0.
+// Based on released ABI: https://github.com/ARM-software/abi-aa, aaelf64.
+// ELF64
+// Null relocation: also 0x100 for ELF64
 ELF_RELOC(R_AARCH64_NONE,                                0)
+// Data relocations
 ELF_RELOC(R_AARCH64_ABS64,                           0x101)
 ELF_RELOC(R_AARCH64_ABS32,                           0x102)
 ELF_RELOC(R_AARCH64_ABS16,                           0x103)
 ELF_RELOC(R_AARCH64_PREL64,                          0x104)
 ELF_RELOC(R_AARCH64_PREL32,                          0x105)
 ELF_RELOC(R_AARCH64_PREL16,                          0x106)
+// Static relocations
----------------
smithp35 wrote:

If this is intended to match the text in aaelf64 then it should be `Static AArch64 Relocations` https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst#static-aarch64-relocations

The reason I'm being picky is Static relocations also include the Data relocations.

Static relocation codes should start at 0x101 (257). R_AARCH64_ABS64 is strange in that it can be both static and dynamic.
```
Static relocation codes for ELF64 object files begin at (257); dynamic ones at (1024). Both (0) and (256) should be accepted as values of R_AARCH64_NONE, the null relocation.
```



https://github.com/llvm/llvm-project/pull/86955