[13] RFR: 8227223: [Graal] Implement basic type consistency checks for Low level MH intrinsics

[Jamsheed]

Request for review for the backport of JDK-8221577 [1] .

The fix [2] was integrated into JDK 14 as part of JDK-8225497:"Update 
Graal" [1].

jdk13 backport webrev: http://cr.openjdk.java.net/~jcm/8227223/webrev.00/

jdk14 webrev: https://cr.openjdk.java.net/~kvn/8221577/webrev.00/ (Thank 
you, Vladimir Kozlov)

bug: https://bugs.openjdk.java.net/browse/JDK-8227223

Description of problem by Vladimir Ivanov:

"Method handle linkers (MethodHandle.linkTo*) are inherently unsafe: 
it's possible to use arbitrary signature to invoke a method and behavior 
is implementation/platform-specific when argument type mismatch occurs 
(e.g., int vs float). Type checking for method handle invocation happens 
earlier: either in MethodHandle.invoke/invokeExact() or as part of 
invokedynamic linkage. MH linkers implement low-level semantics of 
different invocation modes.

Though such type mismatches (int vs float) shouldn't occur at runtime 
(it's guaranteed by how method handles are constructed), JIT-compiler 
can observe it on unreachable branches which can't be proved as such at 
compile-time. (See JDK-8166110 for an example.)

In order to avoid paradoxes in IR, C2 doesn't inline through MH.linkTo* 
methods if there's type mismatch for any argument or return type 
(decision is made in ciMethod::is_consistent_info())."

Best Regards,

Jamsheed

[1] https://bugs.openjdk.java.net/browse/JDK-8221577

[2] 
https://github.com/oracle/graal/commit/d880341edf09d6a14021e2c7f09f70eda56c1c9d