[Tcl] Fix handling of long long on 32-bit platforms

Fixes https://sourceforge.net/p/swig/bugs/977/ reported by Vera and
Kjell Wooding.

Closes #2331

Examples/test-suite/tcl/integers_runme.tcl

@@ -0,0 +1,24 @@
+if [ catch { load ./integers[info sharedlibextension] integers} err_msg ] {
+	puts stderr "Could not load shared object:\n$err_msg"
+}
+
+set val 3902408827
+if {[signed_long_identity $val] != $val} {
+    puts stderr "Runtime test 1 failed"
+    exit 1
+}
+
+if {[unsigned_long_identity $val] != $val} {
+    puts stderr "Runtime test 2 failed"
+    exit 1
+}
+
+if {[signed_long_long_identity $val] != $val} {
+    puts stderr "Runtime test 3 failed"
+    exit 1
+}
+
+if {[unsigned_long_long_identity $val] != $val} {
+    puts stderr "Runtime test 4 failed"
+    exit 1
+}