[llvm] [DebugInfo] Add num_extra_inhabitants to debug info (PR #112590)

[Adrian Prantl via llvm-commits]

================
@@ -225,9 +225,13 @@ namespace llvm {
     /// \param SizeInBits  Size of the type.
     /// \param Encoding    DWARF encoding code, e.g., dwarf::DW_ATE_float.
     /// \param Flags       Optional DWARF attributes, e.g., DW_AT_endianity.
+    /// \param NumExtraInhabitants The number of extra inhabitants of the type.
+    /// An extra inhabitant is a bit pattern that does not represent a valid
+    /// value for instances of a given type.
----------------
adrian-prantl wrote:

Can you add a comment that this is used by the Swift language?

https://github.com/llvm/llvm-project/pull/112590