Sema: do not analyze test decls when not in test mode
We do this by reserving string table indexes 0 and 1 in ZIR to be
special. Decls now have 0 to mean comptime or usingnamespace, and 1 to
mean an unnamed test decl.
fa6bb4b662Andrew Kelley committed on 4/28/2021, 11:57:01 PMparent2354cba