[analyzer] When performing a binary operation on symbolic operands, we convert...

[analyzer] When performing a binary operation on symbolic operands, we convert the symbol values to a common type. But in a relational operation, the result is an 'int' or 'bool', which may not be the appropriate type to convert the operands to. In these cases, use the left-hand operand's type as the conversion type.

There's no associated test for this because fully-constrained symbolic values are evaluated ahead of time in normal expressions. This can only come up in checker-constructed expressions (like the ones in an upcoming patch to CStringChecker).

llvm-svn: 133041