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