[Renderscript] Change expression strings to use portable format specifiers.

Mips64 tests were failing on windows because the sscanf implementation differs between clang/gcc/msvc such that on windows %lx specifies a 32bits parameter and %llx is for 64bits. For us this meant that 64bit pointers were being truncated to 32bits on their way into a JIT'd expression.

llvm-svn: 261741