Auto merge of #124676 - djkoloski:relax_multiple_sanitizers, r=cuviper,rcvalle

Relax restrictions on multiple sanitizers

Most combinations of LLVM sanitizers are legal-enough to enable simultaneously. This change will allow simultaneously enabling ASAN and shadow call stacks on supported platforms.

I used this python script to generate the mutually-exclusive sanitizer combinations:

```python
#!/usr/bin/python3

import subprocess

flags = [
    ["-fsanitize=address"],
    ["-fsanitize=leak"],
    ["-fsanitize=memory"],
    ["-fsanitize=thread"],
    ["-fsanitize=hwaddress"],
    ["-fsanitize=cfi", "-flto", "-fvisibility=hidden"],
    ["-fsanitize=memtag", "--target=aarch64-linux-android", "-march=armv8a+memtag"],
    ["-fsanitize=shadow-call-stack"],
    ["-fsanitize=kcfi", "-flto", "-fvisibility=hidden"],
    ["-fsanitize=kernel-address"],
    ["-fsanitize=safe-stack"],
    ["-fsanitize=dataflow"],
]

for i in range(len(flags)):
    for j in range(i):
        command = ["clang++"] + flags[i] + flags[j] + ["-o", "main.o", "-c", "main.cpp"]
        completed = subprocess.run(command, stderr=subprocess.DEVNULL)
        if completed.returncode != 0:
            first = flags[i][0][11:].replace('-', '').upper()
            second = flags[j][0][11:].replace('-', '').upper()
            print(f"(SanitizerSet::{first}, SanitizerSet::{second}),")
```

1 files changed, 4 insertions, 1 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 6939674ce9d..37b8f81ad94 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -1230,7 +1230,10 @@ fn add_sanitizer_libraries(
     if sanitizer.contains(SanitizerSet::DATAFLOW) {
         link_sanitizer_runtime(sess, flavor, linker, "dfsan");
     }
-    if sanitizer.contains(SanitizerSet::LEAK) {
+    if sanitizer.contains(SanitizerSet::LEAK)
+        && !sanitizer.contains(SanitizerSet::ADDRESS)
+        && !sanitizer.contains(SanitizerSet::HWADDRESS)
+    {
         link_sanitizer_runtime(sess, flavor, linker, "lsan");
     }
     if sanitizer.contains(SanitizerSet::MEMORY) {