[Ada] Style cleanups related to Current_Condition

gcc/ada/

	* einfo.ads (Current_Value): Fix typo in comment.
	* exp_ch2.adb (Expand_Current_Value): Remove unnecessary "Start
	of processing ..." comment.
	* exp_util.adb (Set_Entity_Current_Value): Fix unbalanced paren
	in comment.
	(Get_Current_Value_Condition): Fix layout in comment.
	* sem_ch5.adb (Analyze_Cond_Then): Replace commented condition
	with pragma Assert.

gcc/ada/einfo.ads

@@ -822,7 +822,7 @@ package Einfo is
 --       Defined in all object entities. Set in E_Variable, E_Constant, formal
 --       parameters and E_Loop_Parameter entities if we have trackable current
 --       values. Set non-Empty if the (constant) current value of the variable
---       is known, This value is valid only for references from the same
+--       is known. This value is valid only for references from the same
 --       sequential scope as the entity. The sequential scope of an entity
 --       includes the immediate scope and any contained scopes that are package
 --       specs, package bodies, blocks (at any nesting level) or statement

gcc/ada/exp_ch2.adb

@@ -122,8 +122,6 @@ package body Exp_Ch2 is
       Val : Node_Id;
       Op  : Node_Kind;
 
-   --  Start of processing for Expand_Current_Value
-
    begin
       if True
 

gcc/ada/exp_util.adb

@@ -6418,7 +6418,7 @@ package body Exp_Util is
             if Loc < Sloc (CV) then
                return;
 
-               --  After end of IF statement
+            --  After end of IF statement
 
             elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
                return;
@@ -12741,7 +12741,7 @@ package body Exp_Util is
                --  they occur at the same level. If the second one is nested,
                --  then the decision is neither right nor wrong (it would be
                --  equally OK to leave the outer one in place, or take the new
-               --  inner one. Really we should record both, but our data
+               --  inner one). Really we should record both, but our data
                --  structures are not that elaborate.
 
                if Nkind (Current_Value (Ent)) not in N_Subexpr then

gcc/ada/sem_ch5.adb

@@ -1833,7 +1833,7 @@ package body Sem_Ch5 is
 
             --  If condition is False, analyze THEN with expansion off
 
-            else -- Is_False (Expr_Value (Cond))
+            else pragma Assert (Is_False (Expr_Value (Cond)));
                Expander_Mode_Save_And_Set (False);
                In_Deleted_Code := True;
                Analyze_Statements (Tstm);