Fix sign bit shift

Author: natecook1000

Tests/BinaryParsingTests/FloatingPointTests.swift

@@ -206,7 +206,7 @@ struct FloatingPointTests {
       }
 
       if value.isNaN {
-        #expect(value1.isNaN)
+        #expect(value1.isNaN, )
         #expect(value2.isNaN)
         if value.isSignalingNaN {
           #expect(value1.isSignalingNaN)

Tests/BinaryParsingTests/TestingSupport.swift

@@ -146,7 +146,7 @@ extension Array where Element == UInt8 {
       self.append(contentsOf: bytes)
     }
     let signAndExponent =
-      value.exponentBitPattern | (value.sign == .minus ? 1 : 0 << 31)
+      value.exponentBitPattern | (value.sign == .minus ? 1 : 0) << 15
     Swift.withUnsafeBytes(of: signAndExponent.littleEndian) { bytes in
       self.append(contentsOf: bytes)
     }
@@ -155,7 +155,7 @@ extension Array where Element == UInt8 {
   init(bigEndian value: Float80) {
     self = []
     let signAndExponent =
-      value.exponentBitPattern | (value.sign == .minus ? 1 : 0 << 31)
+      value.exponentBitPattern | (value.sign == .minus ? 1 : 0) << 15
     Swift.withUnsafeBytes(of: signAndExponent.bigEndian) { bytes in
       self.append(contentsOf: bytes)
     }