Import sljit 0.91 (svn r257).

The changes since the last import are:

r257: Add missing ADJUST_LOCAL_OFFSET for ARM64.
r256: Move incorrectly placed array definitions.
r255: More work on testing environment.
r254: Refactor test default output.
r253: Pass entry adress in r12 on PPC-LE.
r252: Optimize calls on MIPS-64.
r251: Several minor fixes.
r250: Add missing SLJIT_IS_FPU_AVAILABLE checks and reorder U and S flags.
r249: Optimize jumps on ARM-64.
r248: Optimize jumps on PowerPC.
r247: MIPS64 support is mostly finished.
r246: MIPS arithmetic.
r245: Start working on MIPS64.
r244: Uniform names for TILE-Gx.
r243: Uniform the names of ARM compilers.
r242: Change ll to l on x86 and rename some instructions on ARM-64.
r241: Improved memory access in PPC and reordering the parameter type flags.
r240: Prepare for more registers on ARM-Thumb2 and renaming TMP_REGISTER to TMP_REG1 on x86.
r239: Prepare for more registers on ARMv5.
r238: Prepare for more registers on TILE-Gx.
r237: Prepare for more registers on MIPS and SPARC.
r236: Prepare for more registers on PPC.
r235: Prepare for more registers on x86.
r234: Most tests are pass on ARM-64 now.
r233: Around 25 test cases are now pass on ARM-64.
r232: More progress on ARM-64 and Thumb2 refactoring.
r231: Some progress an ARM-64 and ARM-T2 refactoring.
r230: Thumb2 code refactoring.
r229: Start working on ARM-64.
r228: Little endian PowerPC systems are supported now by the JIT compiler.
r227: TileGX architecture is now supported. Patch made by Jiong Wang.
r226: Cache flush for android. Patch by  Giuseppe D'Angelo.
r225: Add support for forcibly freeing unused executable memory. Inspired by Carsten Klein.
r224: Few typo fixes.
r223: Reorder madvise and posix_madvise.
r222: The missing sljit_get_float_register_index function is added.
r221: Remove an invalid shift on ARM.
r220: JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
r219: Better code size statistics.
r218: Improvements for x86 and LIR dump.
r217: ICC and SunPro C fixes
r216: A new file for tracking internal changes are added.
r215: Less GNU dependnet Makefile and Intel style assemby for x86-64 systems.
r214: Switch from stdcall to cdecl in x86-32.
r213: Upstreaming minor fixes. Thanks for Daniel Richard G.
r212: Documentation update and a fix for a locking issue.
r211: Renaming temporaries to scratches to match the new name of the register. Does not affect compatibility.
r210: Improving assertions.
r209: Port sljit to SunPro C compiler. Patch by Daniel Richard G.
r208: SLJIT_TEMPORARY_REGx registers are renamed to SLJIT_SCRATCH_REGx.
r207: Removing unused checks.
r206: Optimizations for arm.
r205: Some optimizations on powerpc, mips and sparc.
r204: Rename sljit_emit_cond_value to sljit_emit_op_flags.
r203: Small x86 optimization.
r202: Finish cond_value with AND and INT_OP.
r201: More x86 fixes and improvements.
r200: Rename buf and code to inst.
r199: Replacing constants with instruction names in x86. Greatly improves maintainability.
r198: Only xmm0-xmm5 is volatile on Win64, so xmm6 must be saved.
r197: PowerPC shift right always modifies the carry flag. We may need to restore it.
r196: Rename SLJIT_F* functions to SLJIT_*D
r195: SLJIT_INT_OP works in the same way as SLJIT_SINGLE_OP: the input register arguments must be generated by the output of another instruction with SLJIT_INT_OP flag
r194: Renaming sljit_w to sljit_sw, sljit_i to sljit_si, sljit_h to sljit_sh, and sljit_b to sljit_sb.
r193: ARM single precision support.
r192: Single precision support added for ppc, mips and sparc.
r191: Add single precision support. Only works on x86 now.
r190: Relace C types with sljit types. No functionality change.
r189: Change 0 to NULL for mmap.
r188: Support environments where MAP_ANON is not available.
r187: Adding type descriptors for pointers and doubles (preparing for x32 ABIs and single precision support).