[MC][PowerPC] Replace MCContext::reportFatalError calls with reportError

User errors should use reportError. reportError allows us to continue parsing
the file and collect more diagnostics.

While here, make the diagnostic follow convention, merge tests, and test
line/column numbers.

llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp

@@ -271,14 +271,14 @@ private:
     MCAssembler &MCA = getStreamer().getAssembler();
     int64_t Offset;
     if (!LocalOffset->evaluateAsAbsolute(Offset, MCA))
-      MCA.getContext().reportFatalError(
-          LocalOffset->getLoc(), ".localentry expression must be absolute.");
+      MCA.getContext().reportError(LocalOffset->getLoc(),
+                                   ".localentry expression must be absolute");
 
     switch (Offset) {
     default:
-      MCA.getContext().reportFatalError(
-          LocalOffset->getLoc(),
-          ".localentry expression is not a valid power of 2.");
+      MCA.getContext().reportError(
+          LocalOffset->getLoc(), ".localentry expression must be a power of 2");
+      return 0;
     case 0:
       return 0;
     case 1:

llvm/test/MC/PowerPC/ppc64-localentry-error1.s

@@ -4,8 +4,12 @@
 # RUN: not llvm-mc -triple powerpc64le-unknown-unknown -filetype=obj < %s 2> %t
 # RUN: FileCheck < %t %s
 
+	.globl remote_sym
 sym:
+
+# CHECK: :0: error: .localentry expression must be a power of 2
 	.localentry sym, 123
 
-# CHECK: error: .localentry expression is not a valid power of 2.
+# CHECK: :[[#@LINE+1]]:19: error: .localentry expression must be absolute
+	.localentry sym, remote_sym
 

llvm/test/MC/PowerPC/ppc64-localentry-error2.s

@@ -1,12 +0,0 @@
-
-# RUN: not llvm-mc -triple powerpc64-unknown-unknown -filetype=obj < %s 2> %t
-# RUN: FileCheck < %t %s
-# RUN: not llvm-mc -triple powerpc64le-unknown-unknown -filetype=obj < %s 2> %t
-# RUN: FileCheck < %t %s
-
-	.globl remote_sym
-sym:
-	.localentry sym, remote_sym
-
-# CHECK: error: .localentry expression must be absolute.
-