v: limit -div-by-zero-is-zero influence to just the integer types (for f32 and f64, / produces a +inf or -inf value, and the program continues to run)

Author: spytheman

vlib/v/gen/c/infix.v

@@ -1204,8 +1204,6 @@ fn (mut g Gen) gen_plain_infix_expr(node ast.InfixExpr) {
 	needs_cast := node.left_type.is_number() && node.right_type.is_number()
 		&& node.op in [.plus, .minus, .mul, .div, .mod] && !(g.pref.translated
 		|| g.file.is_translated)
-	is_safe_div := node.op == .div && g.pref.div_by_zero_is_zero
-	is_safe_mod := node.op == .mod && g.pref.div_by_zero_is_zero
 	mut typ := node.promoted_type
 	mut typ_str := g.styp(typ)
 	if needs_cast {
@@ -1219,6 +1217,8 @@ fn (mut g Gen) gen_plain_infix_expr(node ast.InfixExpr) {
 		typ_str = g.styp(typ)
 		g.write('(${typ_str})(')
 	}
+	is_safe_div := node.op == .div && g.pref.div_by_zero_is_zero && typ.is_int()
+	is_safe_mod := node.op == .mod && g.pref.div_by_zero_is_zero && typ.is_int()
 	if node.left_type.is_ptr() && node.left.is_auto_deref_var() && !node.right_type.is_pointer() {
 		g.write('*')
 	} else if !g.inside_interface_deref && node.left is ast.Ident

vlib/v/gen/c/testdata/div_by_zero_is_zero.c.must_have

@@ -1,2 +1,3 @@
 int c = (int)(VSAFE_DIV_int(a , z));
 int d = (int)(VSAFE_MOD_int(a , z));
+f32 fc = (f32)(fa / fz);

vlib/v/gen/c/testdata/div_by_zero_is_zero.out

@@ -2,3 +2,6 @@ a == 42
 z == 0
 c == a / z == 0
 d == a % z == 42
+fa == 42.0
+fz == 0.0
+fc == fa / fz == +inf

vlib/v/gen/c/testdata/div_by_zero_is_zero.vv

@@ -7,3 +7,9 @@ println('a == ${a}')
 println('z == ${z}')
 println('c == a / z == ${c}')
 println('d == a % z == ${d}')
+fa := f32(42)
+fz := f32(0)
+fc := fa / fz
+println('fa == ${fa}')
+println('fz == ${fz}')
+println('fc == fa / fz == ${fc}')