lib: cpp: Rename CONFIG_EXCEPTIONS to CONFIG_CPP_EXCEPTIONS

`CONFIG_EXCEPTIONS` is ambiguous in that the word "exception" may be
used to refer to many different types of exceptions, from the hardware
generated faults and interrupts (aka. exceptions) to the C++
exceptions.

This commit renames the Kconfig `CONFIG_EXCEPTIONS` symbol to
`CONFIG_CPP_EXCEPTIONS` in order to clarify that the symbol refers to
the C++ exceptions and eliminate any ambiguity, and deprecates the old
`CONFIG_EXCEPTIONS` symbol.

Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>

lib/cpp/Kconfig

@@ -75,7 +75,7 @@ config LIB_CPLUSPLUS
 
 if LIB_CPLUSPLUS
 
-config EXCEPTIONS
+config CPP_EXCEPTIONS
 	bool "C++ exceptions support"
 	depends on !NEWLIB_LIBC_NANO
 	help

lib/cpp/Kconfig.deprecated

@@ -12,4 +12,18 @@ config CPLUSPLUS
 
 	  [DEPRECATED] Select CPP instead.
 
+if LIB_CPLUSPLUS
+
+config EXCEPTIONS
+	bool "[DEPRECATED] C++ exceptions support"
+	depends on !NEWLIB_LIBC_NANO
+	select CPP_EXCEPTIONS
+	select DEPRECATED
+	help
+	  This option enables support of C++ exceptions.
+
+	  [DEPRECATED] Select CPP_EXCEPTIONS instead.
+
+endif # LIB_CPLUSPLUS
+
 endmenu