Linux/PA-RISC: Link with --unique=.text.* to help binutils

There is a binutils bug that leads to errors like this:

/usr/lib/gcc/hppa2.0-unknown-linux-gnu/4.6.3/../../../../hppa2.0-unknown-linux-gnu/bin/ld: libCMakeLib.a(cmTarget.cxx.o)(.text+0x12084): cannot reach 00001d28__ZNSspLEPKc@@GLIBCXX_3.4+0, recompile with -ffunction-sections
/usr/lib/gcc/hppa2.0-unknown-linux-gnu/4.6.3/../../../../hppa2.0-unknown-linux-gnu/bin/ld: libCMakeLib.a(cmTarget.cxx.o)(.text+0x12084): cannot handle R_PARISC_PCREL17F for std::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator+=(char const*)@@GLIBCXX_3.4
/usr/lib/gcc/hppa2.0-unknown-linux-gnu/4.6.3/../../../../hppa2.0-unknown-linux-gnu/bin/ld: final link failed: Bad value

Until someone finds out what needs to be fixed in binutils this allows anyone
to compile a working CMake even in debug mode.

CompileFlags.cmake

@@ -62,3 +62,9 @@ endif ()
 if (CMAKE_ANSI_CFLAGS)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CMAKE_ANSI_CFLAGS}")
 endif ()
+
+# avoid binutils problem with large binaries, e.g. when building CMake in debug mode
+# See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50230
+if (CMAKE_SYSTEM_NAME STREQUAL Linux AND CMAKE_SYSTEM_PROCESSOR STREQUAL parisc)
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--unique=.text.*")
+endif ()

bootstrap

@@ -93,6 +93,19 @@ else
   cmake_system_openvms=false
 fi
 
+# Determine whether this is Linux
+if echo "${cmake_system}" | grep Linux >/dev/null 2>&1; then
+  cmake_system_linux=true
+  # find out if it is a HP PA-RISC machine
+  if uname -m | grep parisc >/dev/null 2>&1; then
+    cmake_machine_parisc=true
+  else
+    cmake_machine_parisc=false
+  fi
+else
+  cmake_system_linux=false
+fi
+
 # Choose the generator to use for bootstrapping.
 if ${cmake_system_mingw}; then
   # Bootstrapping from an MSYS prompt.
@@ -678,6 +691,14 @@ if ${cmake_system_haiku}; then
   cmake_ld_flags="${LDFLAGS} -lroot -lbe"
 fi
 
+if ${cmake_system_linux}; then
+  # avoid binutils problem with large binaries, e.g. when building CMake in debug mode
+  # See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50230
+  if ${cmake_machine_parisc}; then
+    cmake_ld_flags="${LDFLAGS} -Wl,--unique=.text.*"
+  fi
+fi
+
 #-----------------------------------------------------------------------------
 # Detect known toolchains on some platforms.
 cmake_toolchains=''