[mips] Port `[wasm] Remove dead handling of RUNTIME_ENTRY relocations.`

Port of commit 8ac37bc3.
RelocInfo::INTERNAL_REFERENCE_ENCODED is used only on mips, mips64
and ppc.

Original commit message:
`The RelocInfo::RUNTIME_ENTRY relocation mode is only used for deopt
points in JavaScript code and should never appear in WebAssembly code.`

Change-Id: Ic595103740dc3c349836114f9cbc815865c5b54c
Reviewed-on: https://chromium-review.googlesource.com/1073420Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Sreten Kovacevic <sreten.kovacevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#53370}

src/wasm/wasm-code-manager.cc

@@ -271,6 +271,7 @@ void WasmCode::Validate() const {
       case RelocInfo::WASM_CALL:
       case RelocInfo::JS_TO_WASM_CALL:
       case RelocInfo::EXTERNAL_REFERENCE:
+      case RelocInfo::INTERNAL_REFERENCE_ENCODED:
       case RelocInfo::OFF_HEAP_TARGET:
       case RelocInfo::COMMENT:
       case RelocInfo::CONST_POOL: