[flang] Make -fget-symbols-sources output deterministic

[klausler]

Summary

The DumpSymbolsSources() routine ordered its output by the addresses
of the names of the symbols, and was susceptible to variation across
environments. Fixed by using a multimap using the values of the names.

[PeteSteinfeld]

All builds, tests, and looks good.

flang/lib/Semantics/semantics.cpp

 #include "flang/Parser/tools.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace Fortran::semantics {
 
-using NameToSymbolMap = std::map<const char *, SymbolRef>;
+using NameToSymbolMap = std::multimap<parser::CharBlock, SymbolRef>;
 static void DoDumpSymbols(llvm::raw_ostream &, const Scope &, int indent = 0);
 static void PutIndent(llvm::raw_ostream &, int indent);
 
 static void GetSymbolNames(const Scope &scope, NameToSymbolMap &symbols) {
   // Finds all symbol names in the scope without collecting duplicates.
   for (const auto &pair : scope) {
-    symbols.emplace(pair.second->name().begin(), *pair.second);
+    symbols.emplace(pair.second->name(), *pair.second);
   }
   for (const auto &pair : scope.commonBlocks()) {
-    symbols.emplace(pair.second->name().begin(), *pair.second);
+    symbols.emplace(pair.second->name(), *pair.second);
   }
   for (const auto &child : scope.children()) {
     GetSymbolNames(child, symbols);
   }
 }
 
 // A parse tree visitor that calls Enter/Leave functions from each checker
 // class C supplied as template parameters. Enter is called before the node's

flang/test/Semantics/getsymbols01.f90

  end subroutine
  recursive pure function f() result(x)
   real, allocatable :: x
   x = 1.0
  end function
 end module
 
 ! RUN: %f18 -fget-symbols-sources -fparse-only %s 2>&1 | FileCheck %s
+! CHECK-COUNT-1:f:{{.*}}getsymbols01.f90, 12, 26-27
 ! CHECK-COUNT-1:mm1:{{.*}}getsymbols01.f90, 2, 8-11
 ! CHECK-COUNT-1:s:{{.*}}getsymbols01.f90, 5, 18-19
-! CHECK-COUNT-1:x:{{.*}}getsymbols01.f90, 5, 21-22
-! CHECK-COUNT-1:y:{{.*}}getsymbols01.f90, 5, 24-25
 ! CHECK-COUNT-1:ss:{{.*}}getsymbols01.f90, 9, 19-21
-! CHECK-COUNT-1:f:{{.*}}getsymbols01.f90, 12, 26-27
+! CHECK-COUNT-1:x:{{.*}}getsymbols01.f90, 5, 21-22
 ! CHECK-COUNT-1:x:{{.*}}getsymbols01.f90, 13, 24-25
+! CHECK-COUNT-1:y:{{.*}}getsymbols01.f90, 5, 24-25

flang/test/Semantics/getsymbols02.f90

 ! Tests -fget-symbols-sources with modules.
 
 PROGRAM helloworld
     use mm2b
     implicit none
     integer::i
     i = callget5()
 ENDPROGRAM
 
 ! RUN: %f18 -fparse-only %S/Inputs/getsymbols02-a.f90
 ! RUN: %f18 -fparse-only %S/Inputs/getsymbols02-b.f90
 ! RUN: %f18 -fget-symbols-sources -fparse-only %s 2>&1 | FileCheck %s
-! CHECK: get5: mm2a
 ! CHECK: callget5: mm2b
+! CHECK: get5: mm2a

flang/test/Semantics/getsymbols03-a.f90

 ! Tests -fget-symbols with INCLUDE
 INCLUDE "Inputs/getsymbols03-b.f90"
 
 program main
  use mm3
  integer :: x
  x = f
 end program
 
 ! RUN: %f18 -fget-symbols-sources -fparse-only %s 2>&1 | FileCheck %s
-! CHECK:mm3:{{.*}}getsymbols03-b.f90, 1, 8-11
 ! CHECK:f:{{.*}}getsymbols03-b.f90, 2, 12-13
 ! CHECK:main:{{.*}}getsymbols03-a.f90, 4, 9-13
+! CHECK:mm3:{{.*}}getsymbols03-b.f90, 1, 8-11
 ! CHECK:x:{{.*}}getsymbols03-a.f90, 6, 13-14

flang/test/Semantics/getsymbols04.f90

 ! Tests -fget-symbols-sources with COMMON.
 program main
   integer :: x
   integer :: y
   common /x/ y
   x = y
 end program
 
 ! RUN: %f18 -fget-symbols-sources -fparse-only %s 2>&1 | FileCheck %s
 ! CHECK:x:{{.*}}getsymbols04.f90, 3, 14-15
-! CHECK:y:{{.*}}getsymbols04.f90, 4, 14-15
 ! CHECK:x:{{.*}}getsymbols04.f90, 5, 11-12
+! CHECK:y:{{.*}}getsymbols04.f90, 4, 14-15

flang/test/Semantics/getsymbols05.f90

 ! Tests -fget-symbols-sources with COMMON.
 program main
   integer :: x
   integer :: y
   block
     integer :: x
     x = y
   end block
   x = y
 end program
 
 ! RUN: %f18 -fget-symbols-sources -fparse-only %s 2>&1 | FileCheck %s
 ! CHECK:x:{{.*}}getsymbols05.f90, 3, 14-15
-! CHECK:y:{{.*}}getsymbols05.f90, 4, 14-15
 ! CHECK:x:{{.*}}getsymbols05.f90, 6, 16-17
+! CHECK:y:{{.*}}getsymbols05.f90, 4, 14-15