[flang] add semantics tests for sync team

[rouson]

Summary

Check several standard-conforming and non-conforming sync memory statements.

[ktras]

LGTM. The only note is that, similar to D114181, D118933, D120097, this test should pass if you take away the XFAIL directive and have all the proper error messages, but flang doesn't currently enforce some of the syntax and constraints stated in the standard:

• C1114 - A team-value shall be of type TEAM_TYPE from the intrinsic module ISO_FORTRAN_ENV (an integer does not currently create an error)
• stat-variable must an integer scalar (both a logical and an integer array do not create errors currently)
• errmsg-variable must be a scalar-default-char-variable (a logical does not currently create an error)
• C1172 - that no specifier shall appear more than once in a given sync-stat-list
• C1173 - that a stat-variable or errmsg-variable in a sync-stat shall not be a coindexed object

It seems appropriate to open up an issue on the github repository pointing this out after this commit is pushed, and referencing this test in the issue.

flang/test/Semantics/synchronization04.f90

+! RUN: %python %S/test_errors.py %s %flang_fc1
+! XFAIL: *
+! This test checks for semantic errors in sync team statements based on the
+! statement specification in section 11.6.6 of the Fortran 2018 standard.
+
+program test_sync_team
+  use iso_fortran_env, only : team_type
+  implicit none
+
+  integer sync_status, co_indexed_integer[*], superfluous_stat, non_scalar(1), not_a_team
+  character(len=128) error_message, co_indexed_character[*], superfluous_errmsg
+  logical invalid_type
+  type(team_type) warriors
+   
+  
+  !___ standard-conforming statement ___
+
+  sync team(warriors)
+  sync team(warriors, stat=sync_status)
+  sync team(warriors,                   errmsg=error_message)
+  sync team(warriors, stat=sync_status, errmsg=error_message)
+ 
+  !___ non-standard-conforming statement ___
+
+  !______ missing or invalid team-value _____________________
+
+  !ERROR: TBD
+  sync team(not_a_team)
+
+  !ERROR: expected ')'
+  sync team(stat=sync_status, errmsg=error_message)
+
+  !______ invalid sync-stat-lists: invalid stat= ____________
+
+  !ERROR: expected ')'
+  sync team(warriors, status=sync_status)
+
+  ! Stat-variable must an integer scalar
+  !ERROR: TBD
+  sync team(warriors, stat=invalid_type)
+
+  ! Stat-variable must an integer scalar
+  !ERROR: TBD
+  sync team(warriors, stat=non_scalar)
+
+  ! Invalid sync-stat-list: missing stat-variable
+  !ERROR: expected ')'
+  sync team(warriors, stat)
+
+  ! Invalid sync-stat-list: missing 'stat='
+  !ERROR: expected ')'
+  sync team(warriors, sync_status)
+
+  !______ invalid sync-stat-lists: invalid errmsg= ____________
+
+  ! Invalid errmsg-variable keyword
+  !ERROR: expected ')'
+  sync team(warriors, errormsg=error_message)
+
+  !ERROR: TBD
+  sync team(warriors, errmsg=invalid_type)
+
+  ! Invalid sync-stat-list: missing 'errmsg='
+  !ERROR: expected ')'
+  sync team(warriors, error_message)
+
+  ! Invalid sync-stat-list: missing errmsg-variable
+  !ERROR: expected ')'
+  sync team(warriors, errmsg)
+
+  !______ invalid sync-stat-lists: redundant sync-stat-list ____________
+
+  ! No specifier shall appear more than once in a given sync-stat-list
+  !ERROR: to be determined
+  sync team(warriors, stat=sync_status, stat=superfluous_stat)
+
+  ! No specifier shall appear more than once in a given sync-stat-list
+  !ERROR: to be determined
+  sync team(warriors, errmsg=error_message, errmsg=superfluous_errmsg)
+ 
+  !______ invalid sync-stat-lists: coindexed stat-variable ____________
+
+  ! Check constraint C1173 from the Fortran 2018 standard
+  !ERROR: to be determined
+  sync team(warriors, stat=co_indexed_integer[1])
+ 
+  ! Check constraint C1173 from the Fortran 2018 standard
+  !ERROR: to be determined
+  sync team(warriors, errmsg=co_indexed_character[1])
+
+end program test_sync_team