* src/hc08/ralloc.c (packRegisters),
* src/mcs51/ralloc.c (packRegisters),
* src/SDCCcse.c (cseBBlock): check if result is a symbol first to fix
bug 1750318
* src/SDCCicode.h: POINTER_SET can be true for literals too
* support/regression/tests/bug1750318.c: new, added