Revert "Utils: Remove old compiler support code"

This reverts commit 8a32bcc5e7.

Broke build with MSVC 2015, update 3

Change-Id: Icb59b70fb00ea2a2ecc8d26c8177d21d82aaccf2
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/libs/utils/smallstringiterator.h

@@ -28,6 +28,11 @@
 #include <cstddef>
 #include <iterator>
 
+#pragma push_macro("noexcept")
+#ifndef __cpp_noexcept
+#define noexcept
+#endif
+
 namespace Utils {
 
 namespace Internal {
@@ -146,3 +151,5 @@ private:
 } // namespace Internal
 
 } // namespace Utils
+
+#pragma pop_macro("noexcept")