[baseline] Fix compilation on platforms without sparkplug

A few of the changes added by https://crrev.com/c/3229379 are
causing compilation errors on platforms without sparkplug.

Change-Id: Ic6088b33ba910ae5a96881fa7609e30d35db5d8a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3226548Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#77456}

src/baseline/baseline-batch-compiler.cc

@@ -365,6 +365,8 @@ namespace v8 {
 namespace internal {
 namespace baseline {
 
+class ConcurrentBaselineCompiler {};
+
 BaselineBatchCompiler::BaselineBatchCompiler(Isolate* isolate)
     : isolate_(isolate),
       compilation_queue_(Handle<WeakFixedArray>::null()),
@@ -379,6 +381,8 @@ BaselineBatchCompiler::~BaselineBatchCompiler() {
   }
 }
 
+void BaselineBatchCompiler::InstallBatch() { UNREACHABLE(); }
+
 }  // namespace baseline
 }  // namespace internal
 }  // namespace v8

src/flags/flag-definitions.h

@@ -709,6 +709,8 @@ DEFINE_NEG_IMPLICATION(concurrent_sparkplug, write_protect_code_memory)
 #endif
 #else
 DEFINE_BOOL(baseline_batch_compilation, false, "batch compile Sparkplug code")
+DEFINE_BOOL_READONLY(concurrent_sparkplug, false,
+                     "compile Sparkplug code in a background thread")
 #endif
 DEFINE_STRING(sparkplug_filter, "*", "filter for Sparkplug baseline compiler")
 DEFINE_BOOL(sparkplug_needs_short_builtins, false,