Fix 2 LLVM assertion caoused by an API missues in Scalar

[tberghammer]

Summary

Fix 2 LLVM assertion caused by an API miss-ues in Scalar

APInt::trunc only works if the destination size is strictly smaller
then the source size while APInt::sext and APInt::zext only works if
the destination size is strictly larger then the source size.

[labath]

Could you please add one or two unit tests for this in ScalarTest?

[tberghammer]

Abandoning. as rL270062 fixed the same issue before I managed to add a test for this CL.

source/Core/Scalar.cpp

switch (m_type)
         case Scalar::e_long_double:
             break;
             
         case Scalar::e_sint:
         case Scalar::e_slong:
         case Scalar::e_slonglong:
         case Scalar::e_sint128:
         case Scalar::e_sint256:
-            m_integer = m_integer.ashr(bit_offset).trunc(bit_size).sext(8 * GetByteSize());
+        {
+            m_integer = m_integer.ashr(bit_offset);
+            if (m_integer.getBitWidth() > bit_size)
+                m_integer = m_integer.trunc(bit_size);
+            if (m_integer.getBitWidth() < bit_size)
+                m_integer = m_integer.sext(8 * GetByteSize());
             return true;
+        }
 
         case Scalar::e_uint:
         case Scalar::e_ulong:
         case Scalar::e_ulonglong:
         case Scalar::e_uint128:
         case Scalar::e_uint256:
-            m_integer = m_integer.lshr(bit_offset).trunc(bit_size).zext(8 * GetByteSize());
+        {
+            m_integer = m_integer.lshr(bit_offset);
+            if (m_integer.getBitWidth() > bit_size)
+                m_integer = m_integer.trunc(bit_size);
+            if (m_integer.getBitWidth() < bit_size)
+                m_integer = m_integer.zext(8 * GetByteSize());
             return true;
         }
+    }
     return false;
 }
 
 bool
 lldb_private::operator== (const Scalar& lhs, const Scalar& rhs)
 {
     // If either entry is void then we can just compare the types
     if (lhs.m_type == Scalar::e_void || rhs.m_type == Scalar::e_void)