Implement struct array field analysis

[presenthee]

Summary

• Added struct_array_field analysis to analyze the consecutive fields which are used as an array in the source code
  • Select target structs by seeing its type
  • By using andersen analysis, find .offset accesses to target struct fields
  • Rewrite only if the pointee type of the accessed pointer and target field type are the same.
• Perform struct_array_field rewriting before pointer rewriting

Test

Rewrite the following struct in 7 test cases

#[derive(Copy, Clone)]
#[repr(C)]
pub struct c2Simplex {
    pub a: c2sv,
    pub b: c2sv,
    pub c: c2sv,
    pub d: c2sv,
    pub div: core::ffi::c_float,
    pub count: core::ffi::c_int,
}

#[repr(C)]
#[derive(Copy, Clone)]
pub struct c2Simplex {
    pub a: [c2sv; 4],
    pub div: f32,
    pub count: i32,
}

Run on test-corpus:
Summary:

• Test Cases Discovered: 338
• Test Cases Skipped: 2
• Test Cases Tested: 331
• Test Cases Failed: 37