[build] Have one build target for all v8 fuzzers.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 2347be6be86af5af240b6f0f2d72ca3e4f03ff55..9e186fe02ce9aebdc0ff2a8df6970db7cfac0dfe 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -2490,14 +2490,10 @@ group("gn_all") {
 
   deps = [
     ":d8",
+    ":v8_fuzzers",
     ":v8_hello_world",
     ":v8_parser_shell",
     ":v8_sample_process",
-    ":v8_simple_json_fuzzer",
-    ":v8_simple_parser_fuzzer",
-    ":v8_simple_regexp_fuzzer",
-    ":v8_simple_wasm_asmjs_fuzzer",
-    ":v8_simple_wasm_fuzzer",
     "test:gn_all",
     "tools:gn_all",
   ]
@@ -2511,6 +2507,26 @@ group("gn_all") {
   }
 }
 
+group("v8_fuzzers") {
+  testonly = true
+  deps = [
+    ":v8_simple_json_fuzzer",
+    ":v8_simple_parser_fuzzer",
+    ":v8_simple_regexp_fuzzer",
+    ":v8_simple_wasm_asmjs_fuzzer",
+    ":v8_simple_wasm_call_fuzzer",
+    ":v8_simple_wasm_code_fuzzer",
+    ":v8_simple_wasm_data_section_fuzzer",
+    ":v8_simple_wasm_function_sigs_section_fuzzer",
+    ":v8_simple_wasm_fuzzer",
+    ":v8_simple_wasm_globals_section_fuzzer",
+    ":v8_simple_wasm_imports_section_fuzzer",
+    ":v8_simple_wasm_memory_section_fuzzer",
+    ":v8_simple_wasm_names_section_fuzzer",
+    ":v8_simple_wasm_types_section_fuzzer",
+  ]
+}
+
 if (is_component_build) {
   v8_component("v8") {
     sources = [