ASAN (AddressSanitizer) binaries crash with SIGSEGV intermittently during initialization on WSL2

### Windows Version

Microsoft Windows [Version 10.0.22631.4169]

### WSL Version

2.6.3.0

### Are you using WSL 1 or WSL 2?

- [x] WSL 2
- [ ] WSL 1

### Kernel Version

Linux version 6.6.87.2-microsoft-standard-WSL2

### Distro Version

Ubuntu 22.04.5 LTS

### Other Software

Clang/LLVM 14.0.0 (Ubuntu clang version 14.0.0-1ubuntu1.1)
AFL++ 4.33c

### Repro Steps

1. Create a minimal C file:

cat > test_asan.c << 'EOF'
int main() { return 0; }
EOF

2. Compile with ASAN:

clang -fsanitize=address -g test_asan.c -o test_asan

3. Run 20 times in a loop:

for i in $(seq 1 20); do
./test_asan 2>/dev/null || echo "CRASH run $i (exit $?)"
done

### Expected Behavior

All 20 runs should exit with code 0.
A program that does nothing (main returns 0) should never crash.

### Actual Behavior

~30% of runs exit with SIGSEGV (exit 139), with no ASAN output.

Root cause (identified via strace): ASAN shadow memory initialization
uses mmap(MAP_FIXED) to reserve specific virtual address ranges:

mmap(0x603000000000, ..., MAP_FIXED, ...)
mmap(0x603e00000000, ..., MAP_FIXED, ...)
mmap(0x60b000000000, ..., MAP_FIXED, ...)
... (several more fixed-address mappings)

On successful runs, all mappings succeed. On failing runs,
WSL2's ASLR has already placed other mappings at these addresses,
causing MAP_FIXED to fail → SIGSEGV during ASAN initialization,
before any user code executes.

Note: The bug does not reproduce under strace (strace changes the
memory layout, avoiding the conflict).

Setting ASAN_OPTIONS=detect_leaks=0 does NOT fix the issue.

### Diagnostic Logs