Generate all the benchmarks to run.

Instead of requiring the need to maintain a list of all the benchmarks,
add a programmatic way to generate all of the benchmarks.

This generation runs the benchmarks in alphabetical order.

Add a new macro BIONIC_BENCHMARK_WITH_ARG that will be the default argument
to pass to the benchmark. Change the benchmarks that require default arguments.

Add a small example xml file, and remove the full.xml/host.xml files.

Update readme.

Test: Ran new unit tests, verified all tests are added.
Change-Id: I8036daeae7635393222a7a92d18f34119adba745
diff --git a/benchmarks/stdio_benchmark.cpp b/benchmarks/stdio_benchmark.cpp
index 76e9ddb..d547fed 100644
--- a/benchmarks/stdio_benchmark.cpp
+++ b/benchmarks/stdio_benchmark.cpp
@@ -59,22 +59,22 @@
 void BM_stdio_fread(benchmark::State& state) {
   ReadWriteTest(state, fread, true);
 }
-BIONIC_BENCHMARK(BM_stdio_fread);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fread, "AT_COMMON_SIZES");
 
 void BM_stdio_fwrite(benchmark::State& state) {
   ReadWriteTest(state, fwrite, true);
 }
-BIONIC_BENCHMARK(BM_stdio_fwrite);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fwrite, "AT_COMMON_SIZES");
 
 void BM_stdio_fread_unbuffered(benchmark::State& state) {
   ReadWriteTest(state, fread, false);
 }
-BIONIC_BENCHMARK(BM_stdio_fread_unbuffered);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fread_unbuffered, "AT_COMMON_SIZES");
 
 void BM_stdio_fwrite_unbuffered(benchmark::State& state) {
   ReadWriteTest(state, fwrite, false);
 }
-BIONIC_BENCHMARK(BM_stdio_fwrite_unbuffered);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fwrite_unbuffered, "AT_COMMON_SIZES");
 
 #if !defined(__GLIBC__)
 static void FopenFgetlnFclose(benchmark::State& state, bool no_locking) {
@@ -165,12 +165,12 @@
 static void BM_stdio_fopen_fgetc_fclose_locking(benchmark::State& state) {
   FopenFgetcFclose(state, false);
 }
-BIONIC_BENCHMARK(BM_stdio_fopen_fgetc_fclose_locking);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fopen_fgetc_fclose_locking, "1024");
 
 void BM_stdio_fopen_fgetc_fclose_no_locking(benchmark::State& state) {
   FopenFgetcFclose(state, true);
 }
-BIONIC_BENCHMARK(BM_stdio_fopen_fgetc_fclose_no_locking);
+BIONIC_BENCHMARK_WITH_ARG(BM_stdio_fopen_fgetc_fclose_no_locking, "1024");
 
 static void BM_stdio_printf_literal(benchmark::State& state) {
   while (state.KeepRunning()) {