[clang] [Clang] Implement the core language parts of P2786 - Trivial relocation (PR #127636)

[via cfe-commits]

================
@@ -0,0 +1,272 @@
+// RUN: %clang_cc1 -std=c++2c -verify %s
+
+class Trivial {};
+struct NonRelocatable {
+    ~NonRelocatable();
+};
+static NonRelocatable NonRelocatable_g;
+
+class A trivially_relocatable_if_eligible {};
+class B trivially_relocatable_if_eligible : Trivial{};
+class C trivially_relocatable_if_eligible {
+    int a;
+    void* b;
+    int c[3];
+    Trivial d[3];
+    NonRelocatable& e = NonRelocatable_g;
----------------
cor3ntin wrote:

Can't have volatile members, there are a bunch of tests for const but I added one

https://github.com/llvm/llvm-project/pull/127636