Platform: attempt to split out the bionic modulemap

This splits out the bionic modulemap from the glibc modulemap.  They are
sufficiently different that the duplication is worth it.  Furthermore,
it will enable properly identifying the libc on android.  Once fully
detangled, this will enable the use of bionic on non-android platforms.

Author: compnerd

stdlib/public/Platform/CMakeLists.txt

@@ -95,7 +95,11 @@ foreach(sdk ${SWIFT_SDKS})
       set(GLIBC_ARCH_INCLUDE_PATH "${SWIFT_SDK_${sdk}_ARCH_${arch}_PATH}${GLIBC_ARCH_INCLUDE_PATH}")
     endif()
 
-    set(glibc_modulemap_source "glibc.modulemap.gyb")
+    if(sdk STREQUAL ANDROID)
+      set(glibc_modulemap_source "bionic.modulemap.gyb")
+    else()
+      set(glibc_modulemap_source "glibc.modulemap.gyb")
+    endif()
     set(glibc_modulemap_out "${module_dir}/glibc.modulemap")
 
     # Configure the module map based on the target. Each platform needs to