RFR: JDK-8149466: configure failed after JDK-8148351

[Yasumasa Suenaga]

Hi all,

After JDK-8148351, configure script failed as below: 

----
 configure: Using default toolchain gcc (GNU Compiler Collection) 
 checking for gcc... /usr/lib64/ccache/gcc 
 checking resolved symbolic links for CC... /usr/bin/ccache 
 configure: Please use --enable-ccache instead of providing a wrapped compiler. 
 configure: error: /usr/lib64/ccache/gcc is a symbolic link to ccache. This is not supported. 
 configure exiting with result code 1 
----

I added --enable-ccache to configure option, but I cannot avoid this error. 
Cause of this is that symlink check in toolchain.m4 did not treat --enable-ccache. 

I've uploaded webrev for this issue.
Could you review it?

  http://cr.openjdk.java.net/~ysuenaga/JDK-8149466/webrev.00/


Thanks,

Yasumasa