fix: register custom exceptions despite the target site

[vbreuss]

Every type derived from System.Exception inherits TargetSite, which requires unreferenced code, so the generator never registered a custom exception. Under Native AOT, a snapshot of a custom exception therefore lost its own members, and comparing two of them failed because reflection is switched off.

TargetSite only returns null where the metadata of the method was trimmed, as it always does under Native AOT, so reading it is safe. The generator now registers such an exception with all its members, like reflection finds them, and suppresses the trimming warning on the registration that reads TargetSite. An exception with its own unreferenceable member is still skipped.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Test Results

     92 files       92 suites   2h 16m 14s ⏱️
 38 393 tests  38 392 ✅ 1 💤 0 ❌
223 516 runs  223 515 ✅ 1 💤 0 ❌

Results for commit 042d0f5.

[github-actions]

🚀 Benchmark Results

Details

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.5 LTS (Noble Numbat)

AMD EPYC 9V45 2.60GHz, 1 CPU, 4 logical and 2 physical cores

.NET SDK 10.0.303

[Host] : .NET 8.0.32 (8.0.32, 8.0.3226.50405), X64 RyuJIT x86-64-v4
Job=InProcess  Toolchain=InProcessEmitToolchain  IterationCount=15

LaunchCount=1  WarmupCount=10

Method	Mean	vs aweXpect	Error	StdDev	Gen0	Gen1	Allocated	vs aweXpect
Contains_aweXpect	183.51 ns		5.492 ns	4.869 ns	0.0443	-	744 B
Contains_FluentAssertions	205.66 ns	+12%	10.523 ns	9.843 ns	0.0961	0.0002	1608 B	+116%
Contains_TUnit	208.08 ns	+13%	4.933 ns	3.852 ns	0.0505	-	848 B	+14%
Equivalency_aweXpect	6,536.93 ns		96.553 ns	85.592 ns	0.2289	-	3880 B
Equivalency_FluentAssertions	169,517.77 ns	+2493%	2,821.503 ns	2,639.235 ns	35.1563	1.9531	590288 B	+15114%
Equivalency_TUnit	9,960.56 ns	+52%	320.909 ns	284.478 ns	0.9308	-	15680 B	+304%
EventTriggered_aweXpect	392.65 ns		12.987 ns	12.148 ns	0.1106	0.0005	1856 B
EventTriggered_FluentAssertions	30,589.40 ns	+7691%	1,059.727 ns	991.269 ns	0.3052	0.2747	5256 B	+183%
Int_GreaterThan_aweXpect	77.99 ns		3.539 ns	3.137 ns	0.0319	-	536 B
Int_GreaterThan_FluentAssertions	129.38 ns	+66%	2.632 ns	2.333 ns	0.0730	-	1224 B	+128%
Int_GreaterThan_TUnit	124.21 ns	+59%	4.075 ns	3.812 ns	0.0463	-	776 B	+45%
ItemsCount_AtLeast_aweXpect	151.70 ns		3.250 ns	2.881 ns	0.0358	-	600 B
ItemsCount_AtLeast_FluentAssertions	254.31 ns	+68%	7.716 ns	7.217 ns	0.1197	-	2008 B	+235%
ItemsCount_AtLeast_TUnit	224.97 ns	+48%	6.732 ns	6.297 ns	0.0634	-	1064 B	+77%
Multiple_aweXpect	443.05 ns		7.151 ns	6.339 ns	0.1006	0.0005	1688 B
Multiple_FluentAssertions	1,113.14 ns	+151%	32.250 ns	30.167 ns	0.4025	-	6744 B	+300%
Multiple_TUnit	503.90 ns	+14%	4.460 ns	4.172 ns	0.1335	-	2240 B	+33%
Satisfies_aweXpect	101.41 ns		1.122 ns	0.937 ns	0.0329	-	552 B
Satisfies_FluentAssertions	10,127.51 ns	+9887%	196.140 ns	153.133 ns	0.3357	0.2899	5615 B	+917%
Satisfies_TUnit	136.90 ns	+35%	3.083 ns	2.733 ns	0.0424	-	712 B	+29%
String_aweXpect	154.74 ns		1.440 ns	1.202 ns	0.0343	-	576 B
String_FluentAssertions	293.56 ns	+90%	5.718 ns	5.069 ns	0.1373	-	2304 B	+300%
String_TUnit	189.13 ns	+22%	3.565 ns	2.977 ns	0.0544	-	912 B	+58%
StringArray_aweXpect	342.05 ns		6.242 ns	4.874 ns	0.0520	-	872 B
StringArray_FluentAssertions	732.07 ns	+114%	19.388 ns	18.136 ns	0.2480	-	4152 B	+376%
StringArray_TUnit	332.99 ns	-3%	8.550 ns	7.140 ns	0.0753	-	1264 B	+45%
StringArrayInAnyOrder_aweXpect	336.84 ns		14.679 ns	13.731 ns	0.0548	-	920 B
StringArrayInAnyOrder_FluentAssertions	10,245.11 ns	+2942%	371.853 ns	347.832 ns	1.9989	0.0610	33471 B	+3538%
StringArrayInAnyOrder_TUnit	449.91 ns	+34%	10.883 ns	9.088 ns	0.0839	-	1408 B	+53%
Throws_aweXpect	6,588.00 ns		32.202 ns	26.890 ns	0.0992	-	1736 B
Throws_FluentAssertions	19,600.82 ns	+198%	101.509 ns	94.952 ns	1.0986	-	18609 B	+972%
Throws_TUnit	6,458.62 ns	-2%	51.329 ns	45.502 ns	0.1068	-	1824 B	+5%
ThrowsAsync_aweXpect	6,212.93 ns		107.840 ns	95.598 ns	0.1297	-	2216 B
ThrowsAsync_FluentAssertions	28,303.89 ns	+356%	194.353 ns	181.798 ns	1.4038	-	23553 B	+963%
ThrowsAsync_TUnit	12,586.19 ns	+103%	121.239 ns	101.240 ns	0.1678	-	2920 B	+32%