Add some overflow protection when setting salience

Author: Ferdinand Neman

.github/ISSUE_TEMPLATE/bug_report.md

@@ -14,7 +14,7 @@ A clear and concise description of what the bug is.
 Steps to reproduce the behavior:
 1. I create code for this and that
 2. With a test for this and that
-3. Instead of seeng this
+3. Instead of seeing this
 4. I see that
 
 **Expected behavior**

ast/Salience.go

@@ -14,6 +14,8 @@
 
 package ast
 
+import "math"
+
 // NewSalience create new Salience AST object
 func NewSalience(val int) *Salience {
 
@@ -34,5 +36,9 @@ type SalienceReceiver interface {
 
 // AcceptIntegerLiteral accept the assigned integer
 func (sal *Salience) AcceptIntegerLiteral(lit *IntegerLiteral) {
-	sal.SalienceValue = int(lit.Integer)
+	if lit.Integer >= math.MinInt32 && lit.Integer <= math.MaxInt32 {
+		sal.SalienceValue = int(lit.Integer)
+	} else {
+		panic("Salience value out of range")
+	}
 }