[build] Make rpath a bit more robust for Mac sanitizers.

Bug: #61713
Bug: #61831
Change-Id: I76ca4ae244dda7d97d98adfb802814a649edc309
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/457882
Commit-Queue: Ryan Macnak <[email protected]>
Reviewed-by: Alexander Aprelev <[email protected]>

Author: rmacnak-google

build/config/compiler/BUILD.gn

@@ -146,6 +146,14 @@ config("compiler") {
       ldflags += [
         "-rpath",
         "buildtools/mac-$host_cpu/clang/lib/clang/22/lib/darwin",
+
+        # Back from xcodebuild/ReleaseTSAN/dart
+        "-rpath",
+        "@loader_path/../../buildtools/mac-$host_cpu/clang/lib/clang/22/lib/darwin",
+
+        # Back from xcodebuild/ReleaseTSAN/dart-sdk/bin/dart
+        "-rpath",
+        "@loader_path/../../../../buildtools/mac-$host_cpu/clang/lib/clang/22/lib/darwin",
       ]
     }