Switch to per-executable contexts in the loader

- Per-executable contexts should be used from now on
  - Global contexts are left as is for now for backwards
    compatibility and will be phased out in follow up
    patches.

Change-Id: I6291abf865c7ed24ee71f5065e539afc23f5ce64

runtime/hsa-runtime/loader/executable.hpp

@@ -423,6 +423,12 @@ public:
       size_t id,
       hsa_default_float_rounding_mode_t default_float_rounding_mode);
 
+  ExecutableImpl(
+      const hsa_profile_t &_profile,
+      std::unique_ptr<Context> unique_context,
+      size_t id,
+      hsa_default_float_rounding_mode_t default_float_rounding_mode);
+
   ~ExecutableImpl();
 
   hsa_status_t GetInfo(hsa_executable_info_t executable_info, void *value) override;
@@ -549,6 +555,7 @@ private:
   amd::hsa::common::ReaderWriterLock rw_lock_;
   hsa_profile_t profile_;
   Context *context_;
+  std::unique_ptr<Context> unique_context_;
   Logger logger_;
   const size_t id_;
   hsa_default_float_rounding_mode_t default_float_rounding_mode_;
@@ -578,6 +585,12 @@ public:
       const char *options,
       hsa_default_float_rounding_mode_t default_float_rounding_mode = HSA_DEFAULT_FLOAT_ROUNDING_MODE_DEFAULT) override;
 
+  Executable* CreateExecutable(
+      std::unique_ptr<Context> isolated_context,
+      hsa_profile_t profile,
+      const char *options,
+      hsa_default_float_rounding_mode_t default_float_rounding_mode = HSA_DEFAULT_FLOAT_ROUNDING_MODE_DEFAULT) override;
+
   hsa_status_t FreezeExecutable(Executable *executable, const char *options) override;
   void DestroyExecutable(Executable *executable) override;