Fix portability issues in 86c43f4e.

INT64_MIN/MAX should be spelled PG_INT64_MIN/MAX, per well established
convention in our sources.  Less obviously, a symbol named DOUBLE causes
problems on Windows builds, so rename that to DOUBLE_CONST; and rename
INTEGER to INTEGER_CONST for consistency.

Also, get rid of incorrect/obsolete hand-munging of yycolumn, and fix
the grammar for float constants to handle expected cases such as ".1".

First two items by Michael Paquier, second two by me.

src/bin/pgbench/exprparse.y

@@ -47,11 +47,11 @@ static PgBenchExpr *make_func(yyscan_t yyscanner, int fnumber, PgBenchExprList *
 
 %type <elist> elist
 %type <expr> expr
-%type <ival> INTEGER function
-%type <dval> DOUBLE
+%type <ival> INTEGER_CONST function
+%type <dval> DOUBLE_CONST
 %type <str> VARIABLE FUNCTION
 
-%token INTEGER DOUBLE VARIABLE FUNCTION
+%token INTEGER_CONST DOUBLE_CONST VARIABLE FUNCTION
 
 /* Precedence: lowest to highest */
 %left	'+' '-'
@@ -76,8 +76,8 @@ expr: '(' expr ')'			{ $$ = $2; }
 	| expr '*' expr			{ $$ = make_op(yyscanner, "*", $1, $3); }
 	| expr '/' expr			{ $$ = make_op(yyscanner, "/", $1, $3); }
 	| expr '%' expr			{ $$ = make_op(yyscanner, "%", $1, $3); }
-	| INTEGER				{ $$ = make_integer_constant($1); }
-	| DOUBLE				{ $$ = make_double_constant($1); }
+	| INTEGER_CONST			{ $$ = make_integer_constant($1); }
+	| DOUBLE_CONST			{ $$ = make_double_constant($1); }
 	| VARIABLE 				{ $$ = make_variable($1); }
 	| function '(' elist ')' { $$ = make_func(yyscanner, $1, $3); }
 	;

src/bin/pgbench/exprscan.l

@@ -123,12 +123,15 @@ newline			[\n]
 				}
 {digit}+		{
 					yylval->ival = strtoint64(yytext);
-					return INTEGER;
+					return INTEGER_CONST;
 				}
 {digit}+(\.{digit}*)?([eE][-+]?{digit}+)?	{
-					yycolumn += yyleng;
 					yylval->dval = atof(yytext);
-					return DOUBLE;
+					return DOUBLE_CONST;
+				}
+\.{digit}+([eE][-+]?{digit}+)?	{
+					yylval->dval = atof(yytext);
+					return DOUBLE_CONST;
 				}
 {alpha}{alnum}*	{
 					yylval->str = pg_strdup(yytext);

src/bin/pgbench/pgbench.c

@@ -1043,7 +1043,7 @@ coerceToInt(PgBenchValue *pval, int64 *ival)
 	{
 		double dval = pval->u.dval;
 		Assert(pval->type == PGBT_DOUBLE);
-		if (dval < INT64_MIN || INT64_MAX < dval)
+		if (dval < PG_INT64_MIN || PG_INT64_MAX < dval)
 		{
 			fprintf(stderr, "double to int overflow for %f\n", dval);
 			return false;