RFR: 8313785: Fix -Wconversion warnings in prims code

[Dean Long]

On Fri, 4 Aug 2023 14:37:07 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> This patch fixes Wconversion in code in the src/hotspot/share/prims directory.  Most of the changes correct the types.  jfieldID's are created with the int offset returned by InstanceKlass::field_offset().
>      int     field_offset      (int index) const { return field(index).offset(); }
> 
> So when we get the field offset back, it's an int.
> 
> Also stackwalker passes jlong, so made that consistent.
> 
> Tested with tier1 on Oracle supported platforms.

src/hotspot/share/prims/jni.cpp line 1906:

> 1904:     o = JvmtiExport::jni_SetField_probe(thread, obj, o, k, fieldID, false, SigType, (jvalue *)&field_value); \
> 1905:   } \
> 1906:   if (SigType == JVM_SIGNATURE_BOOLEAN) { value = (Argument)(((jboolean)value) & 1); } \

This is already done in bool_field_put(), so it is redundant here.  I think it can be safely removed.

src/hotspot/share/prims/jni.cpp line 2099:

> 2097:     JvmtiExport::jni_SetField_probe(thread, nullptr, nullptr, id->holder(), fieldID, true, SigType, (jvalue *)&field_value); \
> 2098:   } \
> 2099:   if (SigType == JVM_SIGNATURE_BOOLEAN) { value = (Argument)(((jboolean)value) & 1); } \

Same as above.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15160#discussion_r1284873690
PR Review Comment: https://git.openjdk.org/jdk/pull/15160#discussion_r1284873793