Android SDK name changes. (swiftlang#758)

* Android SDK name added.

The OSType remains as Linux, but the platform specific files should be
pulled from the android sdk instead of linux.

* Hardcoded linux sdk replaced by $OS for conformance_begin/end objects.

Author: Gonzalo Larralde

Diff for: lib/product.py

@@ -117,8 +117,8 @@ def __init__(self, name):
 
     def generate(self):
         if Configuration.current.target.sdk == OSType.Linux or Configuration.current.target.sdk == OSType.FreeBSD:
-            self.conformance_begin = '${SDKROOT}/lib/swift/linux/${ARCH}/swift_begin.o' 
-            self.conformance_end = '${SDKROOT}/lib/swift/linux/${ARCH}/swift_end.o' 
+            self.conformance_begin = '${SDKROOT}/lib/swift/${OS}/${ARCH}/swift_begin.o' 
+            self.conformance_end = '${SDKROOT}/lib/swift/${OS}/${ARCH}/swift_end.o' 
             return Library.generate(self, ["-shared", "-Wl,-soname," + self.product_name, "-Wl,--no-undefined"])
         else:
             return Library.generate(self, ["-shared"])

Diff for: lib/target.py

@@ -407,6 +407,8 @@ def swift_triple(self):
     def swift_sdk_name(self):
         if self.sdk == OSType.MacOSX:
             return "macosx"
+        elif self.sdk == OSType.Linux and "android" in self.triple:
+            return "android"
         elif self.sdk == OSType.Linux:
             return "linux"
         elif self.sdk == OSType.FreeBSD: