Shorten gyp target names for PNaCl IRT shim

ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp

Index: ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
diff --git a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
index d3d5f2a11a483c68b640fc23b84845576905673a..be566685204d93b2797b5bff9e6cb5cfc23a6ba8 100644
--- a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
+++ b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
@@ -12,7 +12,7 @@
       # We keep the target names in this file short to avoid having really long
       # path names on Windows.
       # https://code.google.com/p/nativeclient/issues/detail?id=3846
-      'target_name': 'shim_aot',
+      'target_name': 'aot',
       'type': 'none',
       'variables': {
         'nlib_target': 'libpnacl_irt_shim.a',
@@ -53,7 +53,7 @@
     # If we ever change that hook interface or change the in-IRT shim's ABI,
     # we would need to clear the translation cache to match the new IRT.
     {
-      'target_name': 'shim_browser',
+      'target_name': 'browser',
       'type': 'none',
       'variables': {
         # Same output file name as shim_aot, so that we don't need to change
@@ -88,7 +88,7 @@
       # Second half of shim library for PNaCl in-browser translation.
       # This half goes into the IRT and is returned by the unstable
       # IRT hook interface.
-      'target_name': 'shim_for_irt',
+      'target_name': 'irt',
       'type': 'none',
       'variables': {
         'nlib_target': 'libpnacl_irt_shim_for_irt.a',