[Gardening][benchmark] Import MSVCRT on Windows

Import functions from standard C library on Windows.

Author: palimondo

benchmark/single-source/CString.swift

@@ -13,6 +13,8 @@
 import TestsUtils
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

benchmark/single-source/Radix2CooleyTukey.swift

@@ -4,6 +4,8 @@
 
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

benchmark/single-source/StringEdits.swift

@@ -13,6 +13,8 @@
 import TestsUtils
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

benchmark/single-source/StringMatch.swift

@@ -13,6 +13,8 @@
 import TestsUtils
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

benchmark/single-source/Walsh.swift

@@ -13,6 +13,8 @@
 import TestsUtils
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif
@@ -89,4 +91,3 @@ public func run_Walsh(_ N: Int) {
     InverseWalshTransform(&data2)
   }
 }
-

benchmark/utils/ArgParse.swift

@@ -12,6 +12,8 @@
 
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

benchmark/utils/DriverUtils.swift

@@ -12,6 +12,8 @@
 
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 import LibProc

benchmark/utils/TestsUtils.swift

@@ -12,6 +12,8 @@
 
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif