fix(patch): import Musl if it can be imported (#29)

Author: zg

Sources/Histogram/Histogram.swift

@@ -14,6 +14,8 @@
 import Darwin
 #elseif canImport(Glibc)
 import Glibc
+#elseif canImport(Musl)
+import Musl
 #endif
 
 import Numerics