Add bpf_test.go to build and fix the tests

bpf_test.go was not listed in testSrcs, which meant it was not run
during the build, but ran and failed with go test android/soong/...

Test: m
Test: go test android/soong/...
Change-Id: I4542640e8ff08e71565ed50617dbe67d86b29b69

bpf/Android.bp

@@ -21,10 +21,14 @@ bootstrap_go_package {
         "blueprint",
         "blueprint-proptools",
         "soong-android",
+        "soong-cc",
         "soong-cc-config",
     ],
     srcs: [
         "bpf.go",
     ],
+    testSrcs: [
+        "bpf_test.go",
+    ],
     pluginFor: ["soong_build"],
 }

bpf/bpf_test.go

@@ -91,6 +91,13 @@ func testContext(bp string) *android.TestContext {
 			src: "",
 		}
 
+		toolchain_library {
+			name: "libgcc_stripped",
+			vendor_available: true,
+			recovery_available: true,
+			src: "",
+		}
+
 		cc_library {
 			name: "libc",
 			no_libgcc: true,