[build] Suppress -Wunused-but-set-var in libxml2

This patch suppresses -Wunused-but-set-variable warning in
libxml2 third party code that does not comply with.

The code that causes the issues is as the following:
1) third_party/libxml2/xpath.c:10489:9: error: variable 'len' set but
not used
2) third_party/libxml2/encoding.c:2397:12: error: variable 'writtentot'
set but not used
3) third_party/libxml2/encoding.c:2572:9: error: variable 'output' set
but not used
4) third_party/libxml2/encoding.c:2570:9: error: variable 'writtentot'
set but not used

Bug: 77973
Change-Id: Id29c0a555421411bac3bcd48dc43cd350867386f
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/libxml2/+/550883
Reviewed-by: Tamir Duberstein <tamird@google.com>
1 file changed
tree: c859a51332a3b997f252516d108c85cafd9ad44f
  1. bakefile/
  2. doc/
  3. example/
  4. include/
  5. macos/
  6. optim/
  7. os400/
  8. python/
  9. result/
  10. test/
  11. vms/
  12. VxWorks/
  13. win32/
  14. xstc/
  15. .gitignore
  16. .gitlab-ci.yml
  17. .travis.yml
  18. acinclude.m4
  19. AUTHORS
  20. autogen.sh
  21. buf.c
  22. buf.h
  23. BUILD.gn
  24. build_glob.py
  25. c14n.c
  26. catalog.c
  27. ChangeLog
  28. check-relaxng-test-suite.py
  29. check-relaxng-test-suite2.py
  30. check-xinclude-test-suite.py
  31. check-xml-test-suite.py
  32. check-xsddata-test-suite.py
  33. chvalid.c
  34. chvalid.def
  35. config.h
  36. configure.ac
  37. CONTRIBUTING
  38. Copyright
  39. dbgen.pl
  40. dbgenattr.pl
  41. debugXML.c
  42. dict.c
  43. DOCBparser.c
  44. elfgcchack.h
  45. enc.h
  46. encoding.c
  47. entities.c
  48. error.c
  49. genChRanges.py
  50. gentest.py
  51. genUnicode.py
  52. global.data
  53. globals.c
  54. hash.c
  55. HTMLparser.c
  56. HTMLtree.c
  57. INSTALL.libxml2
  58. legacy.c
  59. libxml-2.0-uninstalled.pc.in
  60. libxml-2.0.pc.in
  61. libxml.3
  62. libxml.h
  63. libxml.m4
  64. libxml.spec.in
  65. libxml2-config.cmake.in
  66. libxml2.doap
  67. libxml2.syms
  68. list.c
  69. MAINTAINERS
  70. Makefile.am
  71. Makefile.tests
  72. Makefile.win
  73. nanoftp.c
  74. nanohttp.c
  75. NEWS
  76. parser.c
  77. parserInternals.c
  78. pattern.c
  79. README
  80. README.cvs-commits
  81. README.fuchsia
  82. README.tests
  83. README.zOS
  84. regressions.py
  85. regressions.xml
  86. relaxng.c
  87. rngparser.c
  88. runsuite.c
  89. runtest.c
  90. runxmlconf.c
  91. save.h
  92. SAX.c
  93. SAX2.c
  94. schematron.c
  95. testapi.c
  96. testAutomata.c
  97. testC14N.c
  98. testchar.c
  99. testdict.c
  100. testdso.c
  101. testHTML.c
  102. testlimits.c
  103. testModule.c
  104. testOOM.c
  105. testOOMlib.c
  106. testOOMlib.h
  107. testReader.c
  108. testrecurse.c
  109. testRegexp.c
  110. testRelax.c
  111. testSAX.c
  112. testSchemas.c
  113. testThreads.c
  114. testURI.c
  115. testXPath.c
  116. threads.c
  117. timsort.h
  118. TODO
  119. TODO_SCHEMAS
  120. tree.c
  121. trio.c
  122. trio.h
  123. triodef.h
  124. trionan.c
  125. trionan.h
  126. triop.h
  127. triostr.c
  128. triostr.h
  129. uri.c
  130. valid.c
  131. xinclude.c
  132. xlink.c
  133. xml2-config.1
  134. xml2-config.in
  135. xml2Conf.sh.in
  136. xmlcatalog.c
  137. xmlIO.c
  138. xmllint.c
  139. xmlmemory.c
  140. xmlmodule.c
  141. xmlreader.c
  142. xmlregexp.c
  143. xmlsave.c
  144. xmlschemas.c
  145. xmlschemastypes.c
  146. xmlstring.c
  147. xmlunicode.c
  148. xmlwriter.c
  149. xpath.c
  150. xpointer.c
  151. xzlib.c
  152. xzlib.h