This is a high priority issue. Xcode fails to archive even an empty project.

Steps:
1. Create a New Project
2. Build for Release for iOS
3. Open .xcodeproject
4. Menu bar: Product > Archive

Expected: Xcode generates project Archive
Actual: Xcode fails to generate Archive, an error is shown in Xcode:

ld: bitcode bundle could not be generated because '/.../build/Libraries/com.unity.analytics/iOS/platforminfo.a(PlatformInfo.o)' was built without full bitcode. All object files and libraries for bitcode must be generated from Xcode Archive or Install build for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

or

ld: bitcode bundle could not be generated because '/.../Libraries/com.unity.analytics/iOS/platforminfo.a(PlatformInfo.o)' was built without full bitcode. All object files and libraries for bitcode must be generated from Xcode Archive or Install build for architecture arm64

Reproduced with: 2018.30b6, 2019.1.0a6 (1bd8cbecde85) (trunk)
Not reproduced with: 2018.2.13f1 (Analytics Library 2.0.16)