COMPMID-3067: Address gcc9 failures

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I048d1d7dda7edf587d37ce83a93b557d8a95754a
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2771
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/core/CL/OpenCL.h b/arm_compute/core/CL/OpenCL.h
index 7be65c8..b87cc67 100644
--- a/arm_compute/core/CL/OpenCL.h
+++ b/arm_compute/core/CL/OpenCL.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019 ARM Limited.
+ * Copyright (c) 2016-2020 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -62,7 +62,7 @@
 {
 public:
     /** Default Constructor */
-    CLSymbols() = default;
+    CLSymbols() noexcept(false);
     /** Load OpenCL symbols from handle
      *
      * @param[in] handle Handle to load symbols from
@@ -141,7 +141,7 @@
 #undef DECLARE_FUNCTION_PTR
 
 private:
-    std::pair<bool, bool> _loaded{ false, false };
+    std::pair<bool, bool> _loaded;
 };
 } // namespace arm_compute
 #endif /* ARM_COMPUTE_OPENCL_H */