disable new large types test on 32-bit platforms to unblock the bots

[shajrawi]

workaround for this error on the bots:

******************** TEST 'Swift(watchsimulator-i386) :: IRGen/big_types_corner_cases.swift' FAILED ********************
06:45:12 Script:
06:45:12 --
06:45:12 /Users/buildnode/jenkins/workspace/oss-swift-package-osx/build/buildbot_osx/swift-macosx-x86_64/bin/swiftc -frontend -target i386-apple-watchos2.0  -module-cache-path '/var/folders/_8/79jmzf2142z2xydc_01btlx00000gn/T/swift-testsuite-clang-module-cachejTXIk2' -sdk /Applications/Xcode-beta.app/Contents/Developer/Platforms/WatchSimulator.platform/Developer/SDKs/WatchSimulator4.0.sdk -swift-version 3 -assume-parsing-unqualified-ownership-sil -enable-large-loadable-types /Users/buildnode/jenkins/workspace/oss-swift-package-osx/swift/test/IRGen/big_types_corner_cases.swift -emit-ir | /Users/buildnode/jenkins/workspace/oss-swift-package-osx/swift/utils/PathSanitizingFileCheck --sanitize 'BUILD_DIR=/Users/buildnode/jenkins/workspace/oss-swift-package-osx/build/buildbot_osx/swift-macosx-x86_64' --sanitize 'SOURCE_DIR=/Users/buildnode/jenkins/workspace/oss-swift-package-osx/swift' --use-filecheck '/Users/buildnode/jenkins/workspace/oss-swift-package-osx/build/buildbot_osx/llvm-macosx-x86_64/./bin/FileCheck' /Users/buildnode/jenkins/workspace/oss-swift-package-osx/swift/test/IRGen/big_types_corner_cases.swift
06:45:12 --

[shajrawi]

@swift-ci Please smoke test and merge

[rintaro]

CHECK-64-LABEL I believe.

[gparker42]

Joe, what bug report are you using to track fixing the bug and re-enabling the test?

[shajrawi]

@gparker42 There's no open bug for it at the moment - just part of the umbrella radar for large loadable types