RFR: JDK-8019729: JDK build HIGHEST compiler optimisation setting isn't valid for Sun C++ compiler

[Tim Bell]

Hi Erik:

> The compiler flag "-xalias_level=basic" is not valid for the Solaris 
> Studio C++ compiler on Solaris, but is currently set for both C and 
> C++ highest optimization flags. Since there are currently no C++ 
> libraries using the highest setting on Solaris, we should just remove 
> the flag for C++.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8019729

Looks good to me.

/Tim

> Patch inline:
>
> diff --git a/common/autoconf/flags.m4 b/common/autoconf/flags.m4
> --- a/common/autoconf/flags.m4
> +++ b/common/autoconf/flags.m4
> @@ -272,11 +272,11 @@
>
>    # Optimization levels
>    if test "x$TOOLCHAIN_TYPE" = xsolstudio; then
> -    CC_HIGHEST="$CC_HIGHEST -fns -fsimple -fsingle 
> -xalias_level=basic -xbuiltin=%all -xdepend -xrestrict -xlibmil"
> +    CC_HIGHEST="$CC_HIGHEST -fns -fsimple -fsingle -xbuiltin=%all 
> -xdepend -xrestrict -xlibmil"
>
>      if test "x$OPENJDK_TARGET_CPU_ARCH" = "xx86"; then
>        # FIXME: seems we always set -xregs=no%frameptr; put it 
> elsewhere more global?
> -      C_O_FLAG_HIGHEST="-xO4 -Wu,-O4~yz $CC_HIGHEST -xregs=no%frameptr"
> +      C_O_FLAG_HIGHEST="-xO4 -Wu,-O4~yz $CC_HIGHEST 
> -xalias_level=basic -xregs=no%frameptr"
>        C_O_FLAG_HI="-xO4 -Wu,-O4~yz -xregs=no%frameptr"
>        C_O_FLAG_NORM="-xO2 -Wu,-O2~yz -xregs=no%frameptr"
>        C_O_FLAG_NONE="-xregs=no%frameptr"
> @@ -289,7 +289,7 @@
>          CXX_O_FLAG_HIGHEST="$CXX_O_FLAG_HIGHEST -xchip=pentium"
>        fi
>      elif test "x$OPENJDK_TARGET_CPU_ARCH" = "xsparc"; then
> -      C_O_FLAG_HIGHEST="-xO4 -Wc,-Qrm-s -Wc,-Qiselect-T0 $CC_HIGHEST 
> -xprefetch=auto,explicit -xchip=ultra"
> +      C_O_FLAG_HIGHEST="-xO4 -Wc,-Qrm-s -Wc,-Qiselect-T0 $CC_HIGHEST 
> -xalias_level=basic -xprefetch=auto,explicit -xchip=ultra"
>        C_O_FLAG_HI="-xO4 -Wc,-Qrm-s -Wc,-Qiselect-T0"
>        C_O_FLAG_NORM="-xO2 -Wc,-Qrm-s -Wc,-Qiselect-T0"
>        C_O_FLAG_NONE=""