Silence harmless warnings on CHERI by using INT2PTR where appropriate

On CHERI, pointers are implemented using unforgeable capabilities that
include bounds and permissions metadata to provide fine-grained spatial
and referential memory safety, as well as revocation by sweeping memory
to provide heap temporal memory safety. In order to ensure round trips
via (u)intptr_t preserve this metadata, (u)intptr_t are themselves
represented as capabilities, not plain integers. In order to catch
programming errors caused by using an integer type other than those to
hold a pointer, CHERI LLVM emits a warning by default whenever a plain
integer is cast directly to a pointer (except for integer constants, so
that idioms like (void *)-1 continue to work), since it is likely the
source of that cast should have been a (u)intptr_t instead. Three
instances of this warning remain when compiling for CHERI (note that
Tcl_SetHashValue internally casts to void *), all of which are harmless;
silence them by using INT2PTR.

generic/tclExecute.c

@@ -6901,7 +6901,7 @@ TEBCresume(
 	iterVarPtr = LOCAL(infoPtr->loopCtTemp);
 	valuePtr = iterVarPtr->value.objPtr;
 	iterNum = valuePtr->internalRep.longValue + 1;
-	TclSetLongObj(valuePtr, iterNum);
+	TclSetLongObj(valuePtr, INT2PTR(iterNum));
 
 	/*
 	 * Check whether all value lists are exhausted and we should stop the