migrate some Cache tests to integration tests

build_tests/simple/Rsconsfile

@@ -1,3 +1,3 @@
 Rscons::Environment.new do |env|
-  env.Program('simple', Dir['*.c'])
+  env.Program('simple.exe', Dir['*.c'])
 end

build_tests/simple/cache_command_change.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env["LIBS"] += ["c"]
+  env.Program('simple.exe', Dir['*.c'])
+end

build_tests/simple/cache_dep_checksum_change.rb

@@ -0,0 +1,3 @@
+Rscons::Environment.new do |env|
+  env.Copy("simple.copy", "simple.c")
+end

build_tests/simple/cache_new_dep1.rb

@@ -0,0 +1,6 @@
+Rscons::Environment.new do |env|
+  env.Object("simple.o", "simple.c")
+  env.process
+  env["LDCMD"] = %w[gcc -o ${_TARGET} simple.o]
+  env.Program('simple.exe', [])
+end

build_tests/simple/cache_new_dep2.rb

@@ -0,0 +1,5 @@
+Rscons::Environment.new do |env|
+  env.Object("simple.o", "simple.c")
+  env["LDCMD"] = %w[gcc -o ${_TARGET} simple.o]
+  env.Program('simple.exe', ["simple.o"])
+end

build_tests/simple/cache_user_dep.rb

@@ -0,0 +1,5 @@
+Rscons::Environment.new do |env|
+  env.Program("simple.exe", "simple.c")
+  user_deps = File.read("user_deps", mode: "rb").split(" ")
+  env.depends("simple.exe", *user_deps)
+end

build_tests/two_sources/cache_strict_deps.rb

@@ -0,0 +1,19 @@
+class StrictBuilder < Rscons::Builder
+  def run(options)
+    target, sources, cache, env = options.values_at(:target, :sources, :cache, :env)
+    command = %W[gcc -o #{target}] + sources.sort
+    unless cache.up_to_date?(target, command, sources, env, strict_deps: true)
+      return false unless env.execute("StrictBuilder #{target}", command)
+      cache.register_build(target, command, sources, env)
+    end
+    target
+  end
+end
+
+Rscons::Environment.new(echo: :command) do |env|
+  env.add_builder(StrictBuilder.new)
+  env.Object("one.o", "one.c", "CCFLAGS" => %w[-DONE])
+  env.Object("two.o", "two.c")
+  sources = File.read("sources", mode: "rb").split(" ")
+  env.StrictBuilder("program.exe", sources)
+end