[8u] RFR: enable -fPIC in hotspot

[Alex Kashchenko]

Hi,

aarch32-jdk8u build currently fails on armv7 during VM linking with the 
following error:

/usr/lib/gcc-cross/arm-linux-gnueabihf/5/../../../../arm-linux-gnueabihf/bin/ld: 
adaptiveFreeList.o: relocation R_ARM_THM_MOVW_ABS_NC against `a local 
symbol' can not be used when making a shared object; recompile with -fPIC

At the same time jdk9 builds fine both natively (in Fedora 23 on armv7) 
and with cross-compilation on x86_64 (using arm-linux-gnueabihf 
toolchain in Ubuntu 15.10).

It looks like this bit in rules.make is inconsistent between jdk8u [1] 
and jdk9 [2] as GENPIC variable is set in jdk8u but check is done on LP64.

Webrev: 
http://cr.openjdk.java.net/~akasko/aarch32/jdk8u/hotspot_pic/webrev.00/

I can create a JBS issue if it will be needed.

References:

  - relevant GCC change [3]
  - similar issue [4]


[1] 
http://hg.openjdk.java.net/aarch32-port/jdk8u/hotspot/file/a87e86998272/make/linux/makefiles/rules.make#l144
[2] 
http://hg.openjdk.java.net/aarch32-port/jdk9/hotspot/file/82b79870e348/make/linux/makefiles/rules.make#l154
[3] https://sourceware.org/ml/binutils/2009-04/msg00395.html
[4] 
http://mail.openjdk.java.net/pipermail/hotspot-dev/2012-August/006278.html

-- 
-Alex