Compile some code for precompilation.

src/precompile.jl

@@ -1,18 +1,12 @@
+struct PrecompilationCompilerParams <: AbstractCompilerParams end
+GPUCompiler.runtime_module(::Compiler{<:Any,PrecompilationCompilerParams}) = GPUCompiler
+
 function _precompile_()
     ccall(:jl_generating_output, Cint, ()) == 1 || return nothing
-    Base.precompile(Tuple{typeof(lower_throw!),LLVM.Module})   # time: 0.17275752
-    Base.precompile(Tuple{typeof(lower_byval),CompilerJob,LLVM.Module,LLVM.Function})   # time: 0.055481136
-    Base.precompile(Tuple{typeof(call!),Builder,GPUCompiler.Runtime.RuntimeMethodInstance,Vector{ConstantExpr}})   # time: 0.022024114
-    Base.precompile(Tuple{Type{GPUInterpreter},CodeCache,Core.MethodTable,UInt64})   # time: 0.014925144
-    Base.precompile(Tuple{typeof(resolve_cpu_references!),LLVM.Module})   # time: 0.014757595
-    Base.precompile(Tuple{typeof(lower_ptls!),LLVM.Module})   # time: 0.013304743
-    Base.precompile(Tuple{Core.kwftype(typeof(load_runtime)),NamedTuple{(:ctx,), Tuple{Context}},typeof(load_runtime),CompilerJob})   # time: 0.012303286
-    Base.precompile(Tuple{typeof(lower_gc_frame!),LLVM.Function})   # time: 0.008227327
-    Base.precompile(Tuple{typeof(llvm_machine),PTXCompilerTarget})   # time: 0.008051048
-    Base.precompile(Tuple{typeof(hide_trap!),LLVM.Module})   # time: 0.007331288
-    Base.precompile(Tuple{typeof(mangle_param),Type,Vector{String}})   # time: 0.003355128
-    isdefined(GPUCompiler, Symbol("#55#59")) && Base.precompile(Tuple{getfield(GPUCompiler, Symbol("#55#59")),ModulePassManager})   # time: 0.001026008
-    Base.precompile(Tuple{typeof(julia_datalayout),PTXCompilerTarget})   # time: 0.001025637
-
-    precompile(emit_llvm, (CompilerJob, Core.MethodInstance))
+    target = NativeCompilerTarget()
+    params = PrecompilationCompilerParams()
+    compiler = Compiler(target, params)
+    source = FunctionSpec(identity, Tuple{Nothing})
+    job = CompilerJob(compiler, source)
+    compile(:asm, job)[1]
 end