Segfault with `^` (caret) operator with string and `UInt` of value zero.

[Demonstrandum]

System & Version

uname:

Arch Linux 4.19.91-lts x86_64 GNU/Linux

versioninfo():

Julia Version 1.4.1
Commit 381693d3df* (2020-04-14 17:20 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i5-7300U CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-8.0.1 (ORCJIT, skylake)

Bug

When I try to apply ^ to a string more than one character long with an unsigned integer with value 0 (when trying to duplicate the string n (zero) times), it segfaults.

julia> "xx" ^ Int(0)    # works
""
julia> "xx" ^ UInt(2)   # works
"xxxx"
julia> "x" ^ UInt(0)    # works
""
julia> "xx" ^ UInt(0)   # segfaults

signal (11): Segmentation fault
in expression starting at REPL[3]:0
unknown function (ip: 0x7f7df8c8d369)
unknown function (ip: 0x7f7df8eb8b0a)
unknown function (ip: 0x7f7df8eb8ef4)
unknown function (ip: 0x7f7e05c9b439)
unknown function (ip: (nil))
Allocations: 962253 (Pool: 961928; Big: 325); GC: 1
[1]    96359 segmentation fault (core dumped)  julia

# Expected:
""