More robust implicit link line detection regex

The regex used by CMAKE_PARSE_IMPLICIT_LINK_INFO to detect link lines
should not match lines that happen to have ".../ld.../..." in them.  A
linker name should match only as the last component of a path.

See issue #9666.

Modules/CMakeParseImplicitLinkInfo.cmake

@@ -26,7 +26,9 @@ function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var log_var)
   if(CMAKE_LINKER)
     get_filename_component(linker ${CMAKE_LINKER} NAME)
   endif()
-  set(linker_regex "^( *|.*/)(${linker}|ld|collect2)")
+  # Construct a regex to match linker lines.  It must match both the
+  # whole line and just the command (argv[0]).
+  set(linker_regex "^( *|.*[/\\])(${linker}|ld|collect2)[^/\\]*( |$)")
   set(log "${log}  link line regex: [${linker_regex}]\n")
   string(REGEX REPLACE "\r?\n" ";" output_lines "${text}")
   foreach(line IN LISTS output_lines)

Tests/CMakeTests/ImplicitLinkInfoTest.cmake.in

@@ -77,6 +77,14 @@ set(linux64_pgf90_libs "pgf90;pgf90_rpm1;pgf902;pgf90rtl;pgftnrtl;nspgc;pgc;rt;p
 set(linux64_pgf90_dirs "/opt/compiler/pgi/linux86-64/8.0-3/lib;/usr/lib64;/usr/lib64/gcc/x86_64-suse-linux/4.1.2")
 list(APPEND platforms linux64_pgf90)
 
+# gcc dummy.c -v # in strange path
+set(linux64_test1_text "
+/this/might/match/as/a/linker/ld/but/it/is/not because the ld is not the last path component
+${linux64_gcc_text}")
+set(linux64_test1_libs "${linux64_gcc_libs}")
+set(linux64_test1_dirs "${linux64_gcc_dirs}")
+list(APPEND platforms linux64_test1)
+
 #-----------------------------------------------------------------------------
 # Sun