[dynarmic] simplify assert macro usage (Only ASSERT/DEBUG_ASSERT are needed) (#2890)

- replace instances of ASSERT() with those where UNREACHABLE() should be used instead
- debuggers exist for a reason, you can't just debug an issue in dynarmic with just printing fancy text... you need to inspect values and alldat - while yes the asserts are "useful"; there is this beautiful thing called backtraces
- this will indirectly speedup the main decoder loop because of the added UNREACHABLE()
- this also removes a bunch of macros that were redundant
- the weird trick of [&](){}() is really funky, just do what everyone has done for the past 30 years and use a `do { <thing> } while(0)` :)

I may or may not have missed one assert or messed up my regex substitutions...

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2890
Reviewed-by: Shinmegumi <shinmegumi@eden-emu.dev>
Reviewed-by: Caio Oliveira <caiooliveirafarias0@gmail.com>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/dynarmic/tests/test_generator.cpp

@@ -306,7 +306,7 @@ std::vector<u16> GenRandomThumbInst(u32 pc, bool is_last_inst, A32::ITState it_s
             } else if (bitstring.substr(0, 8) == "11110100") {
                 bitstring.replace(0, 8, "11111001");
             } else {
-                ASSERT_FALSE("Unhandled ASIMD instruction: {} {}", fn, bs);
+                UNREACHABLE(); // "Unhandled ASIMD instruction: {} {}", fn, bs);
             }
             if (std::find(do_not_test.begin(), do_not_test.end(), fn) != do_not_test.end()) {
                 invalid.emplace_back(InstructionGenerator{bitstring.c_str()});