Fix panic in qasm3 lexer found by the fuzzer (#2170)

Fixes #2168

Author: orpuente-MS

compiler/qsc_qasm3/src/lex/raw.rs

@@ -373,9 +373,13 @@ impl<'a> Lexer<'a> {
                         Err(NumberLexError::Incomplete) => unreachable!(),
                     }
                 }
-                Some('e') => match self.exp() {
+                Some('e' | 'E') => match self.exp() {
                     Ok(()) => Ok(Number::Float),
-                    Err(_) => todo!(),
+                    Err(NumberLexError::None) => unreachable!("we know there is an `e`"),
+                    Err(NumberLexError::Incomplete) => {
+                        unreachable!("this only applies when lexing binary, octal, or hex")
+                    }
+                    Err(err) => Err(err),
                 },
                 None | Some(_) => Ok(Number::Float),
             }
@@ -415,7 +419,7 @@ impl<'a> Lexer<'a> {
                     self.chars.next();
                     self.mid_dot(c1)
                 }
-                Some('e') => match self.exp() {
+                Some('e' | 'E') => match self.exp() {
                     Ok(()) => Ok(Number::Float),
                     Err(NumberLexError::None) => unreachable!(),
                     Err(_) => Err(NumberLexError::EndsInUnderscore),

compiler/qsc_qasm3/src/lex/raw/tests.rs

@@ -798,6 +798,34 @@ fn incomplete_exp() {
     );
 }
 
+#[test]
+fn incomplete_exp2() {
+    check(
+        "0.e3_",
+        &expect![[r#"
+            [
+                Token {
+                    kind: Unknown,
+                    offset: 0,
+                },
+            ]
+        "#]],
+    );
+    check(
+        "1e",
+        &expect![[r#"
+            [
+                Token {
+                    kind: Number(
+                        Float,
+                    ),
+                    offset: 0,
+                },
+            ]
+        "#]],
+    );
+}
+
 #[test]
 fn leading_zero_point() {
     check(