Refactor `PtcInfo` (#2625)

* Refactor `PtcInfo`

This change reduces the coupling of `PtcInfo` by moving relocation
tracking to the backend. `RelocEntry`s remains as `RelocEntry`s through
out the pipeline until it actually needs to be written to the PTC
streams. Keeping this representation makes inspecting and manipulating
relocations after compilations less painful. This is something I needed
to do to patch relocations to 0 to diff dumps.

Contributes to #1125.

* Turn `Symbol` & `RelocInfo` into readonly structs

* Add documentation to `CompiledFunction`

* Remove `Compiler.Compile<T>`

Remove `Compiler.Compile<T>` and replace it by `Map<T>` of the
`CompiledFunction` returned.

1 files changed, 32 insertions, 0 deletions

diff --git a/ARMeilleure/CodeGen/Linking/RelocInfo.cs b/ARMeilleure/CodeGen/Linking/RelocInfo.cs
new file mode 100644
index 00000000..922b8bfe
--- /dev/null
+++ b/ARMeilleure/CodeGen/Linking/RelocInfo.cs
@@ -0,0 +1,32 @@
+using System;
+
+namespace ARMeilleure.CodeGen.Linking
+{
+    /// <summary>
+    /// Represents relocation information about a <see cref="CompiledFunction"/>.
+    /// </summary>
+    readonly struct RelocInfo
+    {
+        /// <summary>
+        /// Gets an empty <see cref="RelocInfo"/>.
+        /// </summary>
+        public static RelocInfo Empty { get; } = new RelocInfo(null);
+
+        private readonly RelocEntry[] _entries;
+
+        /// <summary>
+        /// Gets the set of <see cref="RelocEntry"/>.
+        /// </summary>
+        public ReadOnlySpan<RelocEntry> Entries => _entries ?? Array.Empty<RelocEntry>();
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RelocInfo"/> struct with the specified set of
+        /// <see cref="RelocEntry"/>.
+        /// </summary>
+        /// <param name="entries">Set of <see cref="RelocInfo"/> to use</param>
+        public RelocInfo(RelocEntry[] entries)
+        {
+            _entries = entries ?? Array.Empty<RelocEntry>();
+        }
+    }
+}
\ No newline at end of file