Set types as attributes on the cstruct object

[Schamper]

Closes #113

Some micro benchmarks:

from dissect.cstruct import cstruct

cdef = """
#define X 512

enum MyEnum {
    A,
    B,
    C
};

struct test {
    uint32 a;
};
"""
cs = cstruct()
cs.load(cdef)

Before:

In: %timeit getattr(t.cs, "X")
58.1 ns ± 1.04 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)

In: %timeit getattr(t.cs, "MyEnum")
227 ns ± 0.912 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)

In: %timeit getattr(t.cs, "test")
219 ns ± 1.47 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)

After:

In: %timeit getattr(t.cs, "X")
31.2 ns ± 0.0331 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)

In: %timeit getattr(t.cs, "MyEnum")
33.1 ns ± 0.0884 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)

In: %timeit getattr(t.cs, "test")
31.3 ns ± 0.0571 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)

[codecov]

Codecov Report

❌ Patch coverage is 0% with 68 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (a282438) to head (aa1e186).

Files with missing lines	Patch %	Lines
dissect/cstruct/cstruct.py	0.00%	29 Missing ⚠️
dissect/cstruct/tools/stubgen.py	0.00%	25 Missing ⚠️
dissect/cstruct/parser.py	0.00%	12 Missing ⚠️
dissect/cstruct/types/structure.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #114   +/-   ##
=====================================
  Coverage   0.00%   0.00%           
=====================================
  Files         21      21           
  Lines       2435    2469   +34     
=====================================
- Misses      2435    2469   +34     

Flag	Coverage Δ
unittests	0.00% <0.00%> (ø)

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[Miauwkeru]

Some initial remarks with these changes, some projects fail to build:

• dissect.executable fails because it cannot find the Elf_type. My assumption is because at https://github.com/fox-it/dissect.executable/blob/01df4c2e66227e7f084b98c5c2b97f0b40a8d4f5/dissect/executable/elf/c_elf.py#L396 the types dict doesn't get copied.
• dissect.shellitem fails because the code checks whether something is inside the typedefs which now moved to types: https://github.com/fox-it/dissect.shellitem/blob/16bf53da8d5a31bee57e6788a54b04e761d55108/dissect/shellitem/lnk/lnk.py#L76
• dissect.target: jumplist also fails because of the shellitem issue.

[codspeed-hq]

Merging this PR will degrade performance by 15.45%

⚡ 3 improved benchmarks
❌ 1 regressed benchmark
✅ 4 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	test_benchmark_basic[compiled]	83.2 µs	74.8 µs	+11.28%
⚡	test_benchmark_getattr_types	27.4 µs	14.4 µs	+89.53%
❌	test_benchmark_getattr_typedefs	27.8 µs	32.9 µs	-15.45%
⚡	test_benchmark_getattr_constants	17.2 µs	14.4 µs	+19.19%

---

_{Comparing type-as-attr (aa1e186) with main (a282438)}