RFR[M]: Adding MD5 Intrinsic on x86-64

[Ludovic Henry]

> And I got crash during JDK build on linux-x64:
>
> #  Internal Error (src/hotspot/share/opto/library_call.cpp:5732), pid=18904, tid=19012
> #  assert(field != __null) failed: undefined field
> #
> # Java VM: OpenJDK 64-Bit Server VM (fastdebug 16-internal+0-2020-08-03-1651458.vladimir.kozlov.jdkjdk, mixed mode, 
> tiered, compressed oops, g1 gc, linux-amd64)
> # Problematic frame:
> # V  [libjvm.so+0x11123f4]  LibraryCallKit::load_field_from_object(Node*, char const*, char const*, bool, bool, ciInstanceKlass*)+0x334
>
> Current CompileTask:
> C2:   6204 1305       4       sun.security.provider.DigestBase::engineUpdate (189 bytes)
>
> Stack: [0x0000151bfcfc7000,0x0000151bfd0c8000],  sp=0x0000151bfd0c3ed0,  free space=1011k
> Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
> V  [libjvm.so+0x11123f4]  LibraryCallKit::load_field_from_object(Node*, char const*, char const*, bool, bool, ciInstanceKlass*)+0x334
> V  [libjvm.so+0x11167ea]  LibraryCallKit::get_long_state_from_digestBase_object(Node*)+0x2a
> V  [libjvm.so+0x1116f2d]  LibraryCallKit::inline_digestBase_implCompressMB(Node*, ciInstanceKlass*, bool, unsigned char*, char const*, Node*, Node*, Node*)+0x2cd
> V  [libjvm.so+0x1117467]  LibraryCallKit::inline_digestBase_implCompressMB(int)+0x397
> V  [libjvm.so+0x1121de1]  LibraryIntrinsic::generate(JVMState*)+0x211
> V  [libjvm.so+0x75d61d]  PredicatedIntrinsicGenerator::generate(JVMState*)+0xb8d

Interesting, I did all my work on Linux-x64 but didn't observe that. Let me try to reproduce and come back to you on that.