base,dev,mem-ruby: Rename m5 namespace as gem5

As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.

::m5 became ::gem5.

Change-Id: I250b4354113fcd6005dc4144ae378552cb8f6717
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45437
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>

src/base/coroutine.hh

@@ -41,9 +41,11 @@
 #include <functional>
 #include <stack>
 
+#include "base/compiler.hh"
 #include "base/fiber.hh"
 
-namespace m5
+GEM5_DEPRECATED_NAMESPACE(m5, gem5);
+namespace gem5
 {
 
 /**
@@ -292,6 +294,6 @@ class Coroutine : public Fiber
     CallerType caller;
 };
 
-} //namespace m5
+} //namespace gem5
 
 #endif // __BASE_COROUTINE_HH__

src/base/coroutine.test.cc

@@ -39,7 +39,7 @@
 
 #include "base/coroutine.hh"
 
-using namespace m5;
+using namespace gem5;
 
 /**
  * This test is checking if the Coroutine, once it's created

src/base/stl_helpers.hh

@@ -34,7 +34,11 @@
 #include <type_traits>
 #include <vector>
 
-namespace m5 {
+#include "base/compiler.hh"
+
+GEM5_DEPRECATED_NAMESPACE(m5, gem5);
+namespace gem5
+{
 namespace stl_helpers {
 
 template <typename T, typename Enabled=void>
@@ -69,6 +73,6 @@ operator<<(std::ostream& out, const T &t)
 }
 
 } // namespace stl_helpers
-} // namespace m5
+} // namespace gem5
 
 #endif // __BASE_STL_HELPERS_HH__