[gn] fix up d896e2883e6
That commit already added the new .cpp file to the gn build, but it
missed adding the new dependency to DebugInfoGSYM to Symbolize.
diff --git a/llvm/utils/gn/secondary/llvm/lib/DebugInfo/Symbolize/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/Symbolize/BUILD.gn
index aa15a1b..ef527f6 100644
--- a/llvm/utils/gn/secondary/llvm/lib/DebugInfo/Symbolize/BUILD.gn
+++ b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/Symbolize/BUILD.gn
@@ -4,6 +4,7 @@
"//llvm/include/llvm/Config:config",
"//llvm/lib/DebugInfo/BTF",
"//llvm/lib/DebugInfo/DWARF",
+ "//llvm/lib/DebugInfo/GSYM",
"//llvm/lib/DebugInfo/PDB",
"//llvm/lib/Demangle",
"//llvm/lib/Object",
