Use "Environment" instead of "Rscons::Environment" in build tests

build_tests/shared_library/Rsconscript

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     env["CPPPATH"] << "src/lib"
     libmine = env.SharedLibrary("mine", Rscons.glob("src/lib/*.c"))
     env.Program("test-shared.exe",

build_tests/shared_library/error_unknown_suffix.rb

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     File.open("foo.xyz", "wb") do |fh|
       fh.puts("hi")
     end

build_tests/shared_library/shared_library_cxx.rb

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     env["CPPPATH"] << "src/lib"
     libmine = env.SharedLibrary("mine", Rscons.glob("src/lib/*.cc"))
     env.Program("test-shared.exe",

build_tests/shared_library/shared_library_d.rb

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     env["CPPPATH"] << "src/lib"
     libmine = env.SharedLibrary("mine", Rscons.glob("src/lib/*.d"))
     env.Program("test-shared.exe",

build_tests/shared_library/shared_library_set_shld.rb

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     env["CPPPATH"] << "src/lib"
     env["SHLD"] = "gcc"
     libmine = env.SharedLibrary("mine", Rscons.glob("src/lib/*.c"))