Combine the libm .gitignore

Author: tgross35

.gitignore

@@ -1,5 +1,16 @@
-*.rs.bk
+# Rust files
 Cargo.lock
 target
+
+# Sources for external files
 compiler-rt
 *.tar.gz
+
+# Benchmark cache
+baseline-*
+iai-home
+
+# Temporary files
+*.bk
+*.rs.bk
+.#*