After upgrading the default code model from small to medium on
LoongArch, function calls using expression may fail. This is because the
function call instruction has changed from `bl` to `pcalau18i + jirl`,
but `RuntimeDyld` does not handle out-of-range jumps for this
instruction sequence.

This patch fixes: #136561

Reviewed By: SixWeining

Pull Request: https://github.com/llvm/llvm-project/pull/136563

After implementing CFI instructions in the function prologue, LLDB
testing for RISC-V started failing due to insufficient relocations
(e.g., R_RISCV_SET8, R_RISCV_SET16).

This patch adds support for the necessary RISC-V relocations in MCJIT.

Reverts llvm/llvm-project#132587

Due to causing test failures on several of Linaro's buildbots. Several
MLIR test failures and at least one test timing out.

I doubt it's the patch itself, but instead an issue it has uncovered.
Revert while we dig into that.

Use SymbolStringPtr for Symbol names in LinkGraph. This reduces string interning
on the boundary between JITLink and ORC, and allows pointer comparisons (rather
than string comparisons) between Symbol names. This should improve the
performance and readability of code that bridges between JITLink and ORC (e.g.
ObjectLinkingLayer and ObjectLinkingLayer::Plugins).

To enable use of SymbolStringPtr a std::shared_ptr<SymbolStringPool> is added to
LinkGraph and threaded through to its construction sites in LLVM and Bolt. All
LinkGraphs that are to have symbol names compared by pointer equality must point
to the same SymbolStringPool instance, which in ORC sessions should be the pool
attached to the ExecutionSession.
---------

Co-authored-by: Lang Hames <lhames@gmail.com>

Identified with misc-include-cleaner.

This is necessary for supporting function calls in LLDB expressions for
LoongArch.
This patch is inspired by #99336 and simply extracts the parts related
to RuntimeDyld.

Reviewed By: lhames

Pull Request: https://github.com/llvm/llvm-project/pull/114741