Mark internal_error*() as NORET

This helps avoid false positive warnings about unreachable places in the code.

Author: aitap

src/data.table.h

@@ -143,7 +143,7 @@ uint64_t dtwiddle(double x);
 SEXP forder(SEXP DT, SEXP by, SEXP retGrpArg, SEXP retStatsArg, SEXP sortGroupsArg, SEXP ascArg, SEXP naArg);
 SEXP forderReuseSorting(SEXP DT, SEXP by, SEXP retGrpArg, SEXP retStatsArg, SEXP sortGroupsArg, SEXP ascArg, SEXP naArg, SEXP reuseSortingArg); // reuseSorting wrapper to forder
 int getNumericRounding_C(void);
-void internal_error_with_cleanup(const char *call_name, const char *format, ...);
+NORET void internal_error_with_cleanup(const char *call_name, const char *format, ...);
 
 // reorder.c
 SEXP reorder(SEXP x, SEXP order);
@@ -259,7 +259,7 @@ SEXP islockedR(SEXP x);
 bool need2utf8(SEXP x);
 SEXP coerceUtf8IfNeeded(SEXP x);
 SEXP coerceAs(SEXP x, SEXP as, SEXP copyArg);
-void internal_error(const char *call_name, const char *format, ...);
+NORET void internal_error(const char *call_name, const char *format, ...);
 
 // types.c
 char *end(char *start);