[gn] Make FrontendTests depend on AllTargetsDescs
The CMake build merged most clang unittests into a single binary.
The gn build doesn't (yet?) do this, but as part of that change,
FrontendTests somehow picked up a dependency on AllTargetsDescs,
see https://github.com/llvm/llvm-project/pull/134196#discussion_r2068617059
diff --git a/llvm/utils/gn/secondary/clang/unittests/Frontend/BUILD.gn b/llvm/utils/gn/secondary/clang/unittests/Frontend/BUILD.gn
index 931ca8b..66a33cd 100644
--- a/llvm/utils/gn/secondary/clang/unittests/Frontend/BUILD.gn
+++ b/llvm/utils/gn/secondary/clang/unittests/Frontend/BUILD.gn
@@ -12,6 +12,7 @@
"//clang/lib/Sema",
"//clang/lib/Tooling",
"//llvm/lib/Support",
+ "//llvm/lib/Target:AllTargetsDescs",
"//llvm/lib/TargetParser",
]
sources = [
