CHB: C-Expr: add support for recognizing stack arrays

[sipma]

Currently the expression of the address of an array element on the stack that is indexed by a variable rather than a constant is not recognized as such.

Example:

ssa_R3_7 = (*(((SP_in + r0_1) - 28)));

with the accompanying stack-variable introduction of buf at stack offset 28 (char buf[16]) should be expressed in C as

ssa_R3_7 = buf[r0_1];

test case: array_checks_local_work_O0_lifting_bug_report_04_18