[Chapel Merge] Declare a constructor for ForallOptimizationInfo f

Branch: refs/heads/master
Revision: 18c570f
Author: mppf
Log Message:

Merge pull request #16564 from mppf/fix-gcc-4

Declare a constructor for ForallOptimizationInfo for GCC 4

ForallOptimizationInfo included some code that does not compile with GCC 4.4.
Replace it with a more typical C++ pattern that does compile.

I think the problematic pattern originated in PR #15713.

Reviewed by @e-kayrakli - thanks!

Modified Files:
M compiler/AST/ForallStmt.cpp
M compiler/include/ForallStmt.h

Compare: https://github.com/chapel-lang/chapel/compare/c4fe14029c59...18c570f057ac