Add some precompiles for Test (#37754)

Work improving latency in packages often exploits the tests. It's mildly
annoying when the inference time of methods in Test stands out as the
major contributors, so let's get rid of that annoyance.

Author: timholy

contrib/generate_precompile.jl

@@ -119,6 +119,18 @@ if Libdl !== nothing
     """
 end
 
+Test = get(Base.loaded_modules,
+          Base.PkgId(Base.UUID("8dfed614-e22c-5e08-85e1-65c5234f0b40"), "Test"),
+          nothing)
+if Test !== nothing
+    hardcoded_precompile_statements *= """
+    @assert precompile(Tuple{typeof(Test.do_test), Test.ExecutionResult, Any})
+    @assert precompile(Tuple{typeof(Test.testset_beginend), Tuple{String, Expr}, Expr, LineNumberNode})
+    @assert precompile(Tuple{typeof(Test.finish), Test.DefaultTestSet})
+    @assert precompile(Tuple{typeof(Test.eval_test), Expr, Expr, LineNumberNode, Bool})
+    """
+end
+
 function generate_precompile_statements()
     start_time = time_ns()
     debug_output = devnull # or stdout