[GR-16336] Check fast specs pass with empty inline caches

* To check the uncached specializations work correctly.

Author: eregon

spec/truffle/pre_initialization_spec.rb

@@ -11,8 +11,10 @@
 
 guard -> { TruffleRuby.native? } do
   describe "The pre-initialized context" do
-    it "can be used to run specs, as otherwise this spec run will not have tested pre-initialization" do
-      Truffle::Boot.was_preinitialized?.should == true
+    guard -> { ENV["TRUFFLERUBY_CHECK_PREINITIALIZED_SPEC"] != "false" } do
+      it "can be used to run specs, as otherwise this spec run will not have tested pre-initialization" do
+        Truffle::Boot.was_preinitialized?.should == true
+      end
     end
 
     it "is not used if --engine.UsePreInitializedContext=false is passed" do

src/options.yml

@@ -199,7 +199,7 @@ INTERNAL: # Options for debugging the TruffleRuby implementation
     POW_CACHE: [integer-pow-cache, integer, DEFAULT_CACHE, Cache size for Integer#** with a constant exponent]
     RUBY_LIBRARY_CACHE: [ruby-library-cache, integer, DEFAULT_CACHE, Ruby Library cache size]
 
-    # Inline caches with a non-default size
+    # Inline caches with a non-default size. When adding a new option here, update test/truffle/integration/limit-zero.sh
     THREAD_CACHE: [thread-cache, integer, ['!singleContext ? 0 : ', 1], Cache size of operations that depend on a particular thread]
     IDENTITY_CACHE: [identity-cache, integer, 1, Cache size for inline caches comparing by identity for context-independent objects]
     CONTEXT_SPECIFIC_IDENTITY_CACHE: [context-identity-cache, integer, ['!singleContext ? 0 : ', IDENTITY_CACHE], Cache size for inline caches comparing by identity for context-specific objects]

test/truffle/integration/limit-zero.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+source test/truffle/common.sh.inc
+
+export TRUFFLERUBY_CHECK_PREINITIALIZED_SPEC=false
+jt test fast -- --default-cache=0 --thread-cache=0 --identity-cache=0 --class-cache=0 --array-dup-cache=0 --array-strategy-cache=0 --pack-unroll=0 --global-variable-max-invalidations=0