Fix various typos.

Fix various typos.

	PR testsuite/100159
	PR testsuite/100192

gcc/ChangeLog:

	* builtins.c (expand_builtin): Fix typos and missing comments.
	* dwarf2out.c (gen_subprogram_die): Likewise.
	(gen_struct_or_union_type_die): Likewise.

gcc/fortran/ChangeLog:

	* frontend-passes.c (optimize_expr): Fix typos and missing comments.

gcc/testsuite/ChangeLog:

	* g++.dg/template/nontype29.C: Fix typos and missing comments.
	* gcc.dg/Warray-bounds-64.c: Likewise.
	* gcc.dg/Warray-parameter.c: Likewise.
	* gcc.dg/Wstring-compare.c: Likewise.
	* gcc.dg/format/gcc_diag-11.c: Likewise.
	* gfortran.dg/array_constructor_3.f90: Likewise.
	* gfortran.dg/matmul_bounds_9.f90: Likewise.
	* gfortran.dg/pr78033.f90: Likewise.
	* gfortran.dg/pr96325.f90: Likewise.