[test-suite] Add -fcommon

D75056 is going change defaults from -fcommon to -fno-common. This had
to be reverted because of these failing  test cases:

  FAIL: MultiSource/Applications/JM/ldecod/ldecod.compile_time (1 of 2630)
  FAIL: MultiSource/Applications/JM/lencod/lencod.compile_time (2 of 2630)
  FAIL: MultiSource/Benchmarks/ASC_Sequoia/IRSmk/IRSmk.compile_time (3 of 2630)
  FAIL: MultiSource/Benchmarks/DOE-ProxyApps-C/miniAMR/miniAMR.compile_time (4 of 2630)
  FAIL: MultiSource/Benchmarks/Olden/bh/bh.compile_time (5 of 2630)
  FAIL: MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/timberwolfmc.compile_time (6 of 2630)
  FAIL: MultiSource/Benchmarks/Prolangs-C/compiler/compiler.compile_time (7 of 2630)
  FAIL: MultiSource/Benchmarks/Prolangs-C/loader/loader.compile_time (8 of 2630)
  FAIL: MultiSource/Benchmarks/Prolangs-C/simulator/simulator.compile_time (9 of 2630)

which all failed compiling with "multiple definition of .. " link errors as
a result of this change. So, this adds -fcommon to the CMake files that need this,
and is a prep step for recommiting D75056.

Differential revision: https://reviews.llvm.org/D75557
diff --git a/MultiSource/Applications/JM/ldecod/CMakeLists.txt b/MultiSource/Applications/JM/ldecod/CMakeLists.txt
index c23489c..6df880e 100644
--- a/MultiSource/Applications/JM/ldecod/CMakeLists.txt
+++ b/MultiSource/Applications/JM/ldecod/CMakeLists.txt
@@ -1,4 +1,4 @@
-list(APPEND CPPFLAGS -D__USE_LARGEFILE64 -D_FILE_OFFSET_BITS=64)
+list(APPEND CPPFLAGS -fcommon -D__USE_LARGEFILE64 -D_FILE_OFFSET_BITS=64)
 list(APPEND LDFLAGS -lm)
 set(RUN_OPTIONS -i data/test.264 -o Output/test_dec.yuv -r data/test_rec.yuv)
 llvm_multisource(ldecod)
diff --git a/MultiSource/Applications/JM/lencod/CMakeLists.txt b/MultiSource/Applications/JM/lencod/CMakeLists.txt
index 30eafd1..cd133f9 100644
--- a/MultiSource/Applications/JM/lencod/CMakeLists.txt
+++ b/MultiSource/Applications/JM/lencod/CMakeLists.txt
@@ -1,4 +1,4 @@
-list(APPEND CPPFLAGS -D__USE_LARGEFILE64 -D_FILE_OFFSET_BITS=64)
+list(APPEND CPPFLAGS -fcommon -D__USE_LARGEFILE64 -D_FILE_OFFSET_BITS=64)
 list(APPEND LDFLAGS -lm)
 set(FP_TOLERANCE 0.025)
 if(SMALL_PROBLEM_SIZE)
diff --git a/MultiSource/Benchmarks/ASC_Sequoia/IRSmk/CMakeLists.txt b/MultiSource/Benchmarks/ASC_Sequoia/IRSmk/CMakeLists.txt
index 89c8d8c..3e76752 100644
--- a/MultiSource/Benchmarks/ASC_Sequoia/IRSmk/CMakeLists.txt
+++ b/MultiSource/Benchmarks/ASC_Sequoia/IRSmk/CMakeLists.txt
@@ -1,3 +1,4 @@
+list(APPEND CFLAGS -fcommon)
 list(APPEND LDFLAGS -lm)
 set(RUN_OPTIONS irsmk_input)
 llvm_multisource(IRSmk)
diff --git a/MultiSource/Benchmarks/DOE-ProxyApps-C/miniAMR/CMakeLists.txt b/MultiSource/Benchmarks/DOE-ProxyApps-C/miniAMR/CMakeLists.txt
index ea7ec1d..86e1fcc 100644
--- a/MultiSource/Benchmarks/DOE-ProxyApps-C/miniAMR/CMakeLists.txt
+++ b/MultiSource/Benchmarks/DOE-ProxyApps-C/miniAMR/CMakeLists.txt
@@ -1,4 +1,4 @@
-list(APPEND CPPFLAGS -I.)
+list(APPEND CPPFLAGS -fcommon -I.)
 list(APPEND LDFLAGS -lm)
 set(RUN_OPTIONS --nx 8 --ny 8 --nz 8 --num_tsteps 100)
 llvm_multisource(miniAMR)
diff --git a/MultiSource/Benchmarks/Olden/bh/CMakeLists.txt b/MultiSource/Benchmarks/Olden/bh/CMakeLists.txt
index 193d07c..2b4ff22 100644
--- a/MultiSource/Benchmarks/Olden/bh/CMakeLists.txt
+++ b/MultiSource/Benchmarks/Olden/bh/CMakeLists.txt
@@ -1,4 +1,4 @@
-list(APPEND CPPFLAGS -DTORONTO)
+list(APPEND CPPFLAGS -fcommon -DTORONTO)
 list(APPEND LDFLAGS -lm)
 if(LARGE_PROBLEM_SIZE)
   set(RUN_OPTIONS 40000 30)
diff --git a/MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/CMakeLists.txt b/MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/CMakeLists.txt
index 46fdd96..9b9f0b6 100644
--- a/MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/CMakeLists.txt
+++ b/MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/CMakeLists.txt
@@ -1,2 +1,3 @@
+list(APPEND CPPFLAGS -fcommon)
 list(APPEND LDFLAGS -lm)
 llvm_multisource(timberwolfmc)
diff --git a/MultiSource/Benchmarks/Prolangs-C/compiler/CMakeLists.txt b/MultiSource/Benchmarks/Prolangs-C/compiler/CMakeLists.txt
index b0dc037..7d84050 100644
--- a/MultiSource/Benchmarks/Prolangs-C/compiler/CMakeLists.txt
+++ b/MultiSource/Benchmarks/Prolangs-C/compiler/CMakeLists.txt
@@ -1 +1,2 @@
+list(APPEND CPPFLAGS -fcommon)
 llvm_multisource(compiler)
diff --git a/MultiSource/Benchmarks/Prolangs-C/loader/CMakeLists.txt b/MultiSource/Benchmarks/Prolangs-C/loader/CMakeLists.txt
index 0f71be4..2ea972f 100644
--- a/MultiSource/Benchmarks/Prolangs-C/loader/CMakeLists.txt
+++ b/MultiSource/Benchmarks/Prolangs-C/loader/CMakeLists.txt
@@ -1,2 +1,3 @@
+list(APPEND CPPFLAGS -fcommon)
 list(APPEND LDFLAGS -lm)
 llvm_multisource(loader)
diff --git a/MultiSource/Benchmarks/Prolangs-C/simulator/CMakeLists.txt b/MultiSource/Benchmarks/Prolangs-C/simulator/CMakeLists.txt
index 44e8db1..2ed9d19 100644
--- a/MultiSource/Benchmarks/Prolangs-C/simulator/CMakeLists.txt
+++ b/MultiSource/Benchmarks/Prolangs-C/simulator/CMakeLists.txt
@@ -1,2 +1,3 @@
+list(APPEND CPPFLAGS -fcommon)
 list(APPEND LDFLAGS -lm)
 llvm_multisource(simulator)